LI' 






i905 







Glass 5BM5_ 

Book__^ikMk 



CALIFORNIA STATE HORTICULTURAL COMMISSION. 

ELLWOOD COOPER, Commissioner. 



REPORT OF THE COMMISSIONER 



APPOINTED TO INVESTIGATE THE PREVALENCE OF 



TRYPETA LUDENS IN MEXICO 



^DISTRICTS AFFECTED B Y THE ORANGE WORM. 
^NATURE, HABITS, AND EXTENSION OF THE 
PEST, q METHODS ADOPTED FOR ITS CONTROL. 
q DANGER TO BE APPREHENDED FROM ITS 
INTRODUCTION, ETC. ^ ^ ^ Jt ^ ^ 




SACRAMENTO: 

w. w. SHANNON, : : : : scpkrtxtkxdrvt state printing. 

1905. 



MAP OF ]VIEXICO, 

Showing areas infested by the Orange Worm (Trypeta ludens) and the annual orange product of the different States. 




MfijAPEA INFESTED BY TryPETA LUDENS 

-Area probably infested by Trypeta luden 



• Orangk products, over *5.000 per annum 
W Orange products. *50o to * S.ooo per annum. 

• Orange products,* 500 and under, per annum. 



CALIFORNIA STATE HORTICULTURAL COMMISSION. 



ELLWOOD COOPER, Commissioner 



REPORT OF THE COMMISSIONER 



APPOINTED TO INVESTIGATE THE PREVALENCE OF 



TRYPETA LUDENS IN MEXICO 



q DISTRICTS AFFECTED BY THE ORANGE WORM, 
q NATURE, HABITS, AND EXTENSION OF THE 



PEST, q METHODS ADOPTED FOR ITS CONTROL. 
n DANGER TO B E APPREHENDED FROM ITS 
INTRODUCTION, ETC. jit ^ jt Jt ^ jt 




SACRAMENTO: 
w. w. SHANNON, : : : : superintendent state printing. 

1905. 



.r 






CALIFORNIA 5TATL COMMISSION OF HORTICULTURE,. 



ELLWOOD COOPER Commissioner Santa Barbara. 



JOHN ISAAC ----- Secretary 

ED. M. EHRHORN Deputy 

E. K. CARNES Assistant Deputy 

O. E. BREMNER Second Assistant 

GERTRUDE BIRD Stenographer 



...San Francisco. 
.Mountain View. 

-- Riverside. 

Santa Rosa. 

Sacramento. 



OFFICE: 
Room 41, State Capitol, Sacramento. 
Branch Office, Room 11, Ferry Building, San Francisco. 



c- 






Office of the 
State Horticultural Commissioner. 

Sacramento, Cal., June 25, 1905. 
To His Excellency, George C. Pardee, Governor of Galifornui: 

Sir: In accordance with the instructions issued by you, ordering that 
an investigation be made into the prevatence and spread of the orange 
maggot in Me::ico, and the danger to be apprehended from its intro- 
duction into California, I have had such investigation made, and have 
the honor to present you herewith the report of the same. 
Respectfully submitted. 

ELLWOOD COOPER, 

Commissioner. 



INTRODUCTION. 



For many years past it has been known that there existed in Mexico 
a serious pest of the orange, which, in ■ its larval form, worked in the 
pulp of the fruit, reducing it to a rotten mass unfit for use. As the 
Republic of Mexico is very near to our own State, our orange-growers 
were naturally alarmed at the possibility of the pest crossing the border 
and becoming established in the orchards of this State. This alarm 
was increased when, in November, 1899, Mr. Alexander Craw, the Hor- 
ticultural Quarantine Officer of the State Board of Horticulture, dis- 
covered the pest in a shipment of Mexican oranges from Acapulco, and 
this resulted in the placing of an embargo on all oranges coming into 
this State from Mexico. The result of this embargo was a voluminous 
correspondence between the Department of Fomento, in Mexico, and 
the Department of State at Washington, D. C, which was referred to 
Governor Pardee. This correspondence, the greater part of which was 
published in the First Biennial Report of the Commissioner of Horti- 
culture, pages 43 et seq., led to a request from the Mexican Government, 
through the Department of Fomento, that an agent of the California 
Commission of Horticulture be dispatched to make a thorough investi- 
gation of the prevalence of the orange pest in Mexico, to inspect the 
work which has been done looking to its eradication, and to make a 
report as to the exact condition of matters in the affected districts, in 
order that unnecessary alarm, which our Mexican neighbors believed 
existed among our growers, might be removed. Complying with this 
request, an agent of the Commission of Horticulture, by the advice and 
with the consent of Governor Pardee, was appointed by Ellwood Cooper, 
Commissioner of Horticulture, with instructions that he report to Prof. 
A. L. Herrera, who was appointed to represent the Mexican Govern- 
ment in the investigation, at the City of Mexico, on March 15, 1905. 

In accordance with these instructions the work of investigation was 
commenced on the date above mentioned, Professor Herrera representing 
the Department of Fomento (which branch of the Mexican Government 
has charge of the agricultural and horticultural interests of the Republic), 
and Mr. John Isaac representing the State of California, through the 
Commission of Horticulture. The result of these investigations is given 
in the following report. 

Inasmuch as comparatively little is known, by the greater part of our 
orange-growers, in regard to this pest, and in view of the fact that a very 



6 INTRODUCTION. 

great fear exists as to its introduction and spread in our State, this 
report is devoted to a very full description of this insect, as well as to 
an account of the regions infested and the damage wrought by it. 

In this connection we wish to acknowledge the assistance rendered us 
in this work by Prof. A. L. Herrera and the Department of Fomento 
which he represents. For many years this department of the Mexican 
Government has made a thorough study of this pest and resorted to 
every means possible to check its ravages, and in the following pages 
Ave have availed ourselves of the great fund of information accumulated 
by Professor Herrera. We are also indebted to his department for the 
use of several of ovir illustrations. 



R E PO RX 

ON THE 



MEXICAN ORANGE WORM (TRYPETA LUDENS) 



By JOHN ISAAC. 



To Hon. Ellwood Cooper, State Commissioner of Horticidture^ Sacra- 
mento, California: 
Sir: In accordance with your instructions to visit the Republic of 
Mexico and investigate the extent of territory affected by the Mexican 
orange worm, the amount of damage done, and the danger of the 
Introduction of this pest into California, as conveyed in your letter of 
March 2, 1905, given herewith, I have the honor to hand you my report. 

LETTER OF INSTRUCTIONS. 

Sacramento, Cal.. March 2, 1905. 
To Mr. John Isaac, Sacramento, Cal. : 

Sir: You are hereby appointed and instructed to proceed to the City of Mexico, and, 
on your arrival there, to report to the Honorable Secretary of tlie Foreign Office, in 
order that your mission wliile traveling in that country may be understood. 

An agreement, consummated through the Hon. John Hay, Secretary of State, com- 
municated to His Excellency, George C. Pardee, Governor of the State of California, 
dated at Washington, January 21, 1905, has been referred by His Excellency, with all 
communications relating thereto, to this office for consideration and action. 

You are familiar with this correspondence and the object of your mission, which is 
to investigate the IMorelos orange maggot (Trijpeta hidem) in the different provinces of 
Mexico, and to ascertain the extent of the injury caused by this pest in the orange and 
sweet-lime orchards. 

You are aware of the vast territory devoted to orange-growing in California, and the 
danger of the introduction of said pest into our State. In such an event the loss might 
amount to millions of dollars. 

You will meet Prof. Alfonso L. Herrera, who is the head of the Agricultural Com- 
mission on Parasites, and who has been detailed to accompany you on this mission. 

Your experience in the Quarantine Department of the Horticultural Commission in 
San Francisco, with your knowledge of the propagation of parasitic insects, and a 
general knowledge of entomology, eminently fits you for such a mission. 

In your examination of the orange and lime plantations, in the different districts 
where the pest exists, you will be careful to observe whether the damage is caused solely 
by one species of fruit fly, or by several species. 

You will collect, and send here in alcohol, specimens of the flies, larva and pupa, 



8 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

giving extent of diunago, witli sucli particulars of the natural history as may be impor- 
tant to this office. 

You are aware that the season is short for such an investigation, hence the necessity 

of expediting the work. 

(Signed:) ELLWOOD COOPER, 

State Horticultural Commissioner. 
(Signed:) GEORGE C. PARDEE, 

Governor of the State of California. 
(Signed:) CHARLES F. CURRY, 

Secretary of State. 

In accordance with these instructions I met with the representative 
of the Mexican Government, Prof. A. L. Herrera, on March 15th, and 
the following day in his company called upon General de Cosio, the 
then Chief of the Department of Fomento, to whom I presented my 
credentials. General de Cosio assured me that every possible facility 
which the Mexican Government could afford would be given in the 
prosecution of our work, and Professor Herrera was instructed to place 
all facilities of the Commission of Parasitologia, of which he is the 
chief, at our service. 

In a subsequent meeting it was decided to commence operations in 
the State of Morelos, it being the worst infested section of the Republic, 
and to continue our operations from that point as a center. In the 
course of our investigations we visited all the more important orange 
sections of Mexico, inspecting all orchards in these sections and examin- 
ing large quantities of fruit. The result of these investigations is given 
in the following pages. 

HISTORY OF THE TRYPETA LUDENS. 

The fact that oranges in some portions of Mexico were infested by 
maggots has been known for a very considerable time, but the insect was 
not classified and described until 1878, when the Austrian naturalist, 
Loew, one of the leading authorities on dipterous insects, first described 
it under the name which it now bears, Tn/prtn ludcnx. Since the date 
of its first description by Loew, a great deal of attention has been given 
it by entomologists, and during the past few years, or since California 
has taken measures to prevent its introduction into this State, it has 
become a matter of international importance. 

This insect belongs to the natural order Diptera, or two-winged flies, 
and is related to the common house fly. It also belongs to the family 
Trypetidse, a very numerous family, the greater part of which is 
destructive, the larvas either working on fruit or vegetables, or forming 
galls on the plants which they attack. In fact, the greater part of the 
fruit flies which have done such great damage in some countries belong 
to this family. In our own country we have but one fruit fiy which 
has proved serious, the Trypetn pomonelld, wliicb, in some of the Eastern 
States, is a very serious pest of the apple. Tlie group is a very large 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 9 

one, and many genera are found in the United States. As a rule the 
flies are small, although some of the members of the family are of large 
size. They are usually beautifully marked, the wings being spotted or 
banded, as shown in our illustrations of Trypeta Indens. 

While not described before 1873, the insect and its ravages were well 
known in Mexico for many years prior to that time, as it Avas found in 
several varieties of fruit in the tropical sections, the mango and guava 
being especially subject to its attack. So serious was it upon these fruits 
that it was difficult to find a specimen which did not contain from one 
to ten or twelve worms. In fact, it is generally asserted by Mexican 
entomologists, and by people living in the infested sections and who 
have observed it closely, that the mango is its primal food plant, and 
that the orange is secondary. It is certain that it attacks all three of 
the fruits mentioned and continues its existence in the mango and guava 
during the period when oranges are small, green, and unsuitable for 
food for the larvie of the fly. 

Fruit is attacked by this insect in the early ripening period, and as it 
can not exist in the green fruit, the female fly lays her eggs upon the 
orange at the time the fruit begins to turn color; in the early season 
her eggs are laid in the mango and guava, which ripen during the 
immature period of the orange. The general opinion, and one which is 
sui)ported by the habits and life of the insect, is that it is of tropical 
origin and has followed its food supply from the equatorial regions of 
South America into the tropical sections of Mexico, where it has now 
become firmly established. 

While, as stated, this insect and its ravages had been known to the 
inhabitants of tropical Mexico, it had not been scientifically noted or 
described until 1873, when it was worked up by Loew. It was largely 
•a local plague for many years after this, and attracted but little atten- 
tion; in fact, it was not until California, in the interests of her great 
orange industry, prohibited the importation of Mexican oranges into 
her territory that it came into prominence. Since then Trypeta ludens 
has figured extensively in reports and newspaper articles until it has 
become one of the best known insects. Our orange-growers have stood 
in dread of the introduction of this pest as one of the worst possible 
evils that could befall them. How far these fears are well grounded, 
and how far they are exaggerated, it is the object of the following pages 
to show. In any event the agitation has been salutary in that it has 
forced upon the Mexican Government, and, through this sovirce, upon 
the Mexican orchardists, the absolute necessity of using every means 
to check, if they can not actually annihilate, this scourge, and they 
have worked with such good results that danger to California fruit 
interests from this insect has been reduced to a minimum. Every 
possible means has been resorted to to keep down the pest, even to 



10 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

destroying all fruits whicli it infests, and this work will be continued, 
so that, so far as human efforts can avail, the spread of the fly will be 
checked. 

In a paper on the danger of importing insect pests, published in the 
Yearbook of the U. S. Department of Agriculture for 1897, Dr. L. 0. 
Howard, Chief Entomologist of the Department of Agriculture, gives the 
following, which practically covers all that was known of this insect at 
that time: 

For a number of years it has been known that Mexican oranges sold in the New 
Orleans market occasionally contained maggots. The writer ascertained this when vis- 
iting New Orleans as long ago as 1881, but was unable to secure specimens. In 1887 
Prof. Lawrence Bruner, then an agent of the Division of Entomology, while visiting 
Mexico, secured infested fruit, took it home with him to West Point, Nebr., and suc- 
ceeded in rearing the adult insect, which proved to be a two-winged fly, described in 
1873 from Mexico by Loew, the Austrian naturalist, as Trypeta ludentt. 

According to Bruner's report, this insect was most abundant in the oranges raised in 
the State of Morelos, one hundred miles south of the City of Mexico, and the statement 
was made to him while in the City of Mexico that oranges from Morelos were very liable 
to be thus infested. An article upon the insect was published bj^ Riley in the first vol- 
ume of Insect Life (July, 1888), but no further information as to the natural distribution 
of the species was gained for a number of years. In late December, 18i»4, and again in 
February, 1895, the orange groves of Florida suffered, as will be remembered, to a very 
serious extent from severe cold. Hundreds of thousands of trees were killed and the 
orange crop of that year was practically annihilated. It resulted that during January, 
February, and March, 1895, and again during December, 1895, and January, 1896, orange- 
buyers spread out into the West Indies Islands, and many of them went to Mexico. 
The shipments of ^lexican oranges into the U.nited States took an enormous jump, and 
the markets of our Northern and Eastern States were largely supplied with this fruit. 
Many persons saw the Morelos orange fruit worm in oranges upon their tables for the 
first time during these winters, and many newspapers contained accounts of the sup- 
posedly new insect. In only one case, however, so far as we know, was an effort made 
to trace the exact source of the infested fruit. 

Prof. W. G. Johnson, now of the Maryland Agricultural Experiment Station, but 
then assisting Prof. S. A. Forbes, at Cliampain, 111., found the worms in his own break- 
fast oranges, traced the stock to a particular dealer in Chicago, and from him learned 
that the consignment of which these oranges were a part came from just south of the 
City of Mexico — presumably the State of Morelos. 

For some years past the Mexican oranges have reached the California market early 
in the fall, before the California fruit has ripened. Shipments have been begun as early 
as October and have continued up to December, when the California fruit is fit for con- 
sumption. The occurrence of some of these Morelos maggots in some of this fruit was 
pointed out in certain of the California pajiers during the fall oil896, with the result 
which has already been indicated. 

The shipment of this Mexican fruit through to the northern United States can do no 
possible harm, since this species, so far as known, breeds only in citrus fruits. Even 
did it attack other fruits, such as peaches, pears, and apples, as some of its close allies 
are known to do, the fact that the oranges are shipped in the winter would bar its intro- 
duction. During the seasons following the Florida freezes this fruit was even carried 
into Florida and was found on the tables at the principal winter resorts in that State. 
So little native fruit was left in the State, however, that even this could not be con- 
sidered as very dangerous. The carriage of infested fruit into the State of California, 
however, is qtiite another matter. It arrives there just before the California fruit begins 
to ripen. A Mexican orange containing these maggots thrown away even at some dis- 
tance from an orange orchard might result, as can be readily seen, in the establishment 
of this destructive species in California. There is little wonder, then, at the interest 
felt in the matter by the fruit-growers in that State. 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 11 

In 1894, as we have already stated, an agent of the Division of Entomology was sent 
to Mexico for the purpose of investigating the insects injuriovis to agriculture. This 
agent. Prof. C. H. T. Townsend, reported incidentally upon this insect, although his trip 
was made before the "scare," if we may call it so, had developed. He showed that 
oranges were shipped from Guaymas and Hermosillo, in Sonora. Sonora oranges were 
sent to Chicago and other Eastern points, some going, however, to California to the San 
Francisco market. The Morelos oranges, according to the information which he was 
able to gain, were shipped only as far as the City of Mexico. This, however, we have 
already shown was a mistake. From the Guadalajara region oranges were shipped by 
the carload through to northern points, mainly to Kansas City. The same was the case 
with the oranges of Tamaulipas. He could find no evidence that Trypeta ludens infested 
any oranges except those from the State of Morelos. 

During the winter of 1895-96, however, it was learned from American orange-buyers 
that the Morelos fruit worm existed also in the State of Puebla. 

During his travels in the summer and fall of 1897 in Mexico, Mr. Albert Koebele was 
good enough to further investigate this question of the distribution of this insect. He 
was informed by the agent of the Wells-Fargo Company, at the City of Mexico, in 
October, 1897, that but few oranges are now shipped by this company. A few years 
since, however, large quantities from the State of Morelos were delivered to their office 
by the Interoceanic Railroad, to be shipped to the United States via El Paso, their ulti- 
mate destination being unknown to the agent. The freight agent of the National Rail- 
road informed him that but few oranges were shipped from the State of Morelos ; many, 
however, were shipped from the States farther north, principally for New Orleans and 
Central States. 

The agent of the Interoceanic Railroad informed him tliat some of the fruit was 
sliipped by his railroad, chiefly from Jalapa, and thence to Vera Cruz, and no doubt 
from that place by steamer to New Orleans and other points. It was by this road that, 
in Mr. Koebele's opinion, the largest quantity of the Morelos oranges were exported, 
since their lines run through the States of Morelos and Puebla. This agent stated that 
al)out one hundred carloads are shipped annually from Jalisco. He was informed by 
the agent of the Mexican Central Railroad that but few oranges were shipped from the 
City of Mexico, although a great many were shipped from farther north, and especially 
from the Guadalajara branch, chiefly to St. Louis and Chicago. An experienced fruit 
merchant informed him that he had found the larva in Morelos oranges and also in 
considerable number in those from Michoacan, Puebla, and Jalisco. The same merchant 
also informed him that the National Railroad buys large lots of oranges in the City of 
Mexico for shipment. 

This represents our actual knowledge of the distribution of the species in Mexico 
down to the autumn of 1897. Appreciating the desirability from every point of view of 
exact information on this important question, Professor Townsend was commissioned 
to visit in November and December, 1897, every orange-growing district of Mexico, with 
the exception of Sonora, and to examine into conditions with relation to this one insect. 
He carried out his mission with success, and found, as anticipated by the writer, that 
the orange fruit worm occurs practically wherever oranges are grown to any extent in 
Mexico. Good evidence was gathered of the existence of the species in the following 
localities: Morelos, Cordova, Yautepec, Coatepec, Teoselo, Amacusac, Puente de Ixtla, 
Tollman, Jalapa, San Luis Potosi, Pueblo Nuevo, Cuernavaca, Monterey, Linares, 
Montemorelos, Chihuahua, Guadalajara, Escalon, San Cristobal, Anieca, La Barca, 
Victoria, Tuxpan, Jalisco, Manzanillo, Acapulco, and Guerrero. The fruit flics have 
actually been reared in Washington, D. C, from oranges received from Professor 
Townsend from the City of Mexico, from Cordova, from Jalapa, and from Tampico. 
There is, however, no certainty as to where the Tampico oranges were grown. 

Mexican orange-growers have become more interested in the subject of the California 
opposition to their fruit, and are naturally, though not justifiably, indignant at the 
California call for quarantine or prohibition of their fruit. One of the leading indus- 
trial papers of Mexico, El Progreso, contained a leading article last spring insisting that 
the true cause of the California movement was "the desire which these horticulturists 
have of freeing themselves from the competition which grows more threatening for 
them day by day, and not that of escaping from the problematic infestation." 

The knowledge of the exact details of the life history of Trypeta ludens may prove of 



12 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 



value in this apparent emergency. Unfortunately, the insect lias not been carefully 
studied in its native home by a competent entojnologist. Bruner brought back with 
him, in the early winter, specimens of oranges containing larvae, and from these bred 
the adult fly the following February. All of the oranges showed a more or less well- 
defined outward sign of the depredations of some insect enemy. In one a freshly made 
hole coming to the surface was found, and one of the maggots was observed protruding. 
December 30th several of the larvse had pupated, having left the fruit December 22d. 
The fruit itself had rotted and juolded, and about one half of the pulp had been 

devoured. The tirst adult ap- 
peared February 9th. The 
adults of both sexes were con- 
tined with ripe fruit to see if 
tiiey would oviposit in the 
orange, if not on the tree. 
Experiments failed, however, 
and none of the flies laid 
eggs, all dying after several 
days. Johnson experimented 
with two infested oranges. In 
both instances the fruit was 
perfect, so far as outward 
appearances were concerned. 
There were no visible rui>- 
tures or punctures in the skin, 
and the flavor of the fruit was 
sweet and luscioiis. The mag- 




Female, enlarged. 



Fig. 1. 
(Redrawn from Insect Life, by Howard.) 



gots when first noticed, on January lOtli, 
were about one third of an inch long, of a 
dirty whitish color, and worked their way 
freely through the pulp. The fruit was 
placed in a dish with some larvae, and after 
three or four days became very moldy ; but 
the larvse continued feeding until January 
18th, when two of them having reached the 
length of 11 mm., left the oranges and bur- 
rowed into the ground, one pupating on 
the 21st, and the other on the 24th. The 
first adult, a male, issued February 28th, 
or just thirty-eight days after pupation. 
Four days later the second fly emerged. 

The observations of both Messrs. John- 
son and Bruner show that the fly is hardy 
and will stand considerable neglect. Mr. 
Johnson kept a male and female for sev- 
eral days in close confinement in a glass- 
covered dish, and they were seemingly as 
active as ever when removed. Mr. Bruner 
showed that the flies can stand a consid- 
erable variation in temperature, since on 
several occasions during his experiments the 
the room where his breeding cage stood. 

The oranges received at Washington from Professor Townsend from the City of 
Mexico, Cordova, Jalapa, and Tampico all arrived between November 26 and December 
21, 1897. The first flies were reared January 12, 189S, and between that date and Febru- 
ary 3d, twenty-five active specimens emerged, of which fifteen were females. 

The different stages of the insect, with the exception of the egg, are well indicated by 
the figure. The larva is dirty white, the puparium is light brown, and the adult fly is a 
straw yellow in its general color. The bristles upon its body are black and the stripes 
upon the body are silver yellow. The markings upon the wings, as shown by the figure, 
are brownish velhnv, witli brown edges. 




Fig. 2. 
a, larva; 6, anal segment of same; c, pu- 
parium; d, head of same; a and c, enlarged: 
b, d, and e, still more enlarged. (Reengraved 
from Insect Life, by Howard.) 



lercury fell below the freezing point in 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 13 

So far, the knowledge which we possess of the life history of the 
Trypeta ludens is rather general than specific, as it has not been studied 
as yet by an entomologist. Probably Professor Herrera, of the Para- 
sitological Commission, has paid more attention to it than any one else, 
as it comes directly within the province of his department, and in a 
report to the Minister of Fomento he says: 

Complying with the request of Sr. Ingeniero D. Manuel Fernandez Leal, Minister of 
Fomento, I made a journey to Yautepec, on the 19th of February, 1900, to acquire data 
and tables about the orange worm, and present the following as the result of my inves- 
tigations : 

(1) First, the orange worm exists in Yautepec. 

(2) It is the Trypeta ludens, a dipterous insect. 

(3) It attacks all varieties of oranges in all the orchards, and is also found upon the 
mango, the sweet lime, and the guava. 

(4) In .Tanuary and April they breed in the early orange, in May and June in the 
mango, and diiring the rest of the year in oranges as they ripen during the season, and 
in the latter part of the season they reach their greatest numbers. 

(5) As preventive measures I advise the burning of all the early oranges, the clean- 
ing up of all the orchards, the substitution of live hedges by wire fences, and the 
burning of all fruit which ripens prematurely on the trees. It is very probable that the 
enforcement of these measures for two or three consecutive years in all parts of the 
Mexican Republic invaded by this pest woitld result in its total extirpation. 

■ The seriousness of the Trypeta ludens as a pest was first brought 
strongly to the attention of the Mexican Government by the action of 
the California State Board of Horticulture, when the discovery of worms 
in fruit imported from Acapulco caused an embargo to be placed on all 
oranges from that country. As a result of the action of the State Board 
of Horticulture, the following letter was addressed by Fernandez Leal, 
then Chief of the Department of Fomento, to the governors of all of the 
Mexican States: 

Mexico, January 18, 1900. 

The Horticultural Board of the State of California, having discovered the presence of 
maggots in the Mexican orange, has prohibited the introduction of that fruit from 
Mexico into said State, and has ordered that all consignments of oranges from Mexico 
be destroyed upon their arrival. This measure, which has been adopted on account of 
the fear that the pest may spread to the California orange groves, has attracted the 
attention of the press of the State, which has sounded the note of alarm, suggesting that 
the American Congress take up the matter and pass laws to prevent the importation of 
fruits and plants that are tainted with insect or other pests that are capable of being 
propagated. 

This department considers it unnecessary to enter into consideration of the harm 
that will accrue to Mexican trade in general, and especially to the growers of fruit, if 
they are excluded from the important market of the United States; your well-known 
enlightenment will easily enable you to appreciate the extent of the damage. 

This department being desirous of contributing, to the extent of its powers, toward 
warding off an evil of such magnitude from the planters of the country, has deemed fit 
to address this circular to you, urging upon you the necessity of apprising all growers 
of the fruit in question of the steps taken by the Horticultural Board of California, and 
of encouraging them by all possible means to extirjiate tliis pest which has justly 
alarmed said board. 

Until such time as Mexican growers can attain positive results in said direction, this 
department is of the opinion that, in their own interest, they should abstain from 
exporting oranges which show external signs of having been attacked by the dreaded 



14 REPORT ON THE TRYPETA LL'DENS IN MEXICO. 

insect. All the precaution that can be taken for that purpose will be amply compen- 
sated in the future. 

I forward you copies of three articles published in Nos. 9, 10, and 11 of Volumes 
VII and VIII of the "Fruit World" of Los Angeles, in order that by such means as 
you may consider suitable you may secure their profuse circulation among all inter- 
ested parties in the State which you so ably govern. 

(Signed:) FERNANDEZ LEAL. 

As a result of the attention thus called to this insect an active cam- 
paign has been waged against it in sections where it was known to 
exist, and a wider knowledge of its habitat and life history has been 
obtained. In fact, the Trypeia ludens has become one of the best known 
insects in Mexico, especially in the tropical sections where it prevails, 
and methods of combating it are discussed and resorted to. In some 
of the worst infested sections old orchards have been entirely abandoned 
and destroyed, while in all cases a systematic warfare is carried on against 
it. In aid of this work, the Mexican Government, through the Commis- 
sion of Parasitologia, and under the direction of Professor Herrera, 
has kept a force of men at work through the whole season experiment- 
ing with various means to destroy the insect in any or all of its various 
stages. The principal work along this line has been carried on at 
Yautepec, in Morelos, the center of infestation, and from which point 
all wormy fruit in the markets of northern Mexico finds its way. 

ORIGIN OF THE PEST. 

(Translated from bulletin of the Commission of Parasitologia.) 

"As the orange and mango are not indigenous to Mexico and the pest 
is not reported from other places, it is probable that it originated on 
some other fruit, likely the imported guava, and it is necessary to study 
this matter well, in order that measures may be taken to reach the pest 
in its original habitat. 

"What cause is answerable for the spread of this pest ? This is difti- 
cult to answer. It may arise from a mistaken instinct of the females 
which leads them from their natural food, or, on the contrary, it may 
be owing to their sagacity. For instance, not finding guavas upon 
which to lay their eggs, they have sought the next best food plant, 
being attracted by its odor or agreeable sensation. 

" Mr. Rangel has not observed the larger Trypetx attacking guavas 
when oranges were handy. It is not improbable that there are differ- 
ent species adapted to various conditions. 

"The older residents of Yautepec state that this pest was introduced 
there from Cuernavaca sixty years ago, and complain that the pest is 
still found there in quantity and is a source of infestation to the 
orchards of Yautepec. 

" To prove that the pest of the mango and of the orange are identical 
we transferred the larva' from the one fruit to the other, and they took 



TRYPETA LUDENS 



(MEXICAN ORANGE PEST) 




:i 





S*^*'*^ 






From Drawing by the Comision de Parasitologia Agricola, Mexico. 



.awaauj Axa^iYHT 









TRYPETA LUDENS. 

(Mt'xioan Oraiigo I'cst.) 

1— Male, dorsal view. 

2 — Foniale, dorsal view. 

y, — Pupa. 

4 — Larva. 

.\11 very greatly enlargert. 
.') — Fenialo ovipositing on orange, 

ti— Female ovipositing on guava. 

7 - Female ovijjositing on mango. 
All very Kroatlv rodncod. 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 15 

equally well to both and we bred the mature fly {Trypeta hidens) from 
larvpe in mangoes from Cuernavaca. We also bred the insect in guavas, 
transferring three of the larvae from the mango to the guava, into which 
they burrowed in four to five minutes. 

" On July 23d, a guava was found infested with worms, and from 
this we bred the flies which emerged on August 31st." 

DESCRIPTION OF THE INSECT. 

The Trypeta ludeni^ is a dipterous, or two-winged, insect, belonging 
to the somewhat numerous family Trypetidse. The members of this 
family are mostly small insects, although some of them, as Trypeta 
luden^, reach a good size. All of them are vegetable-eaters, many of 
them in the larval state attacking fruit, and others working on the 
stems of plants, forming galls. They vary in color, as in size, and 
range from light yellow to dark brown. In the lighter species the body 
is often spotted, while the wings are spotted, banded, or otherwise 
prettily marked, as shown in the illustrations herein, ^^'ithin this 
family are discovered some of the worst fruit pests in the world, includ- 
ing the West Australian fruit fly {Tephritis tyroni), which has made 
fruit-growing in that colony, if not impracticable, at least unprofitable, 
and to control which the government has expended immense sums. 
The Ceratitis ca pitta is another member of the family which attacks soft 
fruits and has spread over a great portion of the world. The Trypeta 
pomoiieUa, a serious pest of the apple in some of the Eastern States, 
is also a member of this family, and perhaps the worst at present found 
in the United States. Like the Trypeta ludens, the fruit flies lay their 
eggs under the peel of the ripening fruit. These eggs hatch out in a 
short time into footless grubs, or maggots, as the larva^ of the diptera 
are generally called, and these maggots proceed at once to tunnel into 
the fruit, rendering it unfit for consumption. 

The description of Trypeta ludens as given by Professor Loew in 
1873 still stands, and we give it herewith: 

Pale clay-yellow. Front of a somewhat more bright yellow, of a very moderate 
breadth; the usual frontal bristles black, only the upper ones rather long and strong. 
The yellow antennte almost as long as the face; arista long and slender, with a very 
short and delicate pubescence. Oral opening rather large; oral edge rather sharp. 
Proboscis and palpi yellow, the latter rather broad ; the suctorial flaps somewhat pro- 
longed. The upper side of the thorax of a light, bright clay-yclIow; a sulphur-yellow 
middle stripe, gradually vanishing anteriorly, expanding posteriorly in a cuneiform 
shape, and nowhere well defined ; scutellum sulphur-yellow ; on each side, above the 
root of the wings, a well-marked, pale-yellow longitudinal stripe, which runs from the 
transverse suture to the posterior margin of the thorax; quite on the lateral margin an 
indistinct but broader pale-yellow stripe; the humeral corner and a well-deflned stripe 
on the upper part of the pleurae, reaching to the root of the wings, likewise of a bright 
pale-yellow. The very short pile on the thorax is yellowish ; the usual bristles are black 
or blackish brown. Scutellum with four black bristles. Metathorax clay-yellow. Abdo- 
men with short yellowish pile and with black bristles on its posterior end ; the last 



16 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

segment very much prolonged, much longer than the two preceding ones taken together 
(this character serves easily to distinguish this species from T.fratercubis, which is very 
much like it). Feet yellow, under side of the front femora with several blackish-brown 
bristles. Wings not very broad in comparison to their considerable length ; the rivulets 
on them are pale brownish-yellow, with narrow, but little conspicuous, and not always 
perceptible brown borders; near the posterior margin and on the apex of the wing they 
are altogether brownish; the hyaline spaces between the rivulets are as follows: 1. An 
oblique band, interrupted upon the third longitudinal vein, the anterior part of which 
forms, immediately beyond the stigma, a spot extending from the costa to the third 
longitudinal vein, while the posterior part of the band occupies the portion of the basal 
cell which lies under the stigma, the basis of the discal cell and the second basal cell ; 
2. A broad S-shaped band, which begins at the posterior margin, between the tips of 
the fifth and sixth longitudinal veins, passes between the two cross veins, reaches the 
second longitudinal vein, turns backward and reaches the margin in the vicinity of the 
end of the fourth longitudinal vein; 3. A large triangular spot near the posterior 
margin, which 'tills a considerable part of the second posterior cell, reaches with its tij) 
considerably beyond the fourth longitudinal vein, and almost coalesces here with the 
S-shaped hyaline band. The external costal cell also is hyaline, with the exception of 
its basis, but has a more yellowish tinge than the other hyaline spaces. Stigma rather 
long, almost imperceptibly darker than its surroundings. Cross veins straight and 
steep; the third longitudinal vein distinctly bristly; the end of the fourth longitudinal 
vein turned forward ; the posterior end of the anal cell drawn out in a very narrow, 
long lobe. 

The comparison of the description of Tri/peta frolcrculus and T. liulens shows the 
great resemblance of the two species and an entirely satisfactory distinctive character in 
the different length of the last abdominal segment. The females of these species, which 
unfortunately I have not seen, will probably be easy to distinguish, if attention is paid 
to the size, which is larger in T. ludens, to the somewhat broader cheeks, the longer last 
abdominal segment of this species, and to the course of the third and fourth longitudinal 
veins, which suddenly diverge here, while their divergency in T. fraterculus is much 
more gradual. In using the coloring for distinguishing the two species, a certain 
caution is necessary here, as well as in the other species of this group. 

NUMBER OF GENERATIONS. 

The Trypela ludens completes its life cycle from egg to perfect insect 
in about three months, so that there may be four generations within 
the year. It is stated that it has no dormant period, but breeds 
continuously, and that if there is a break in its food supply it must 
necessarily perish. Its eggs are laid and the young larvae live in the 
ripening fruit. It does not attack fruit until it begins to ripen, avoiding 
all green fruit as unfit food. In tropical Mexico the mango and guava 
ripen between the period of the early and the late orange season, thus 
bridging over the interval and furnishing a continuous suitable food 
supply. The Mexican authorities, basing their argument upon this fact, 
assert that inasmuch as there is in California a very long period when 
there is no suitable fruit ripening, the pest could not exist here, and 
would perish in the interval between one orange season and another. 

Samples of infested guavas have been sent to the Bureau of Ento- 
mology at Washington, D. C, and the insects produced from them have 
belonged to another species, Trypela acidusa, and from this fact some 
little doubt has been cast upon the Trypela ludens attacking the guava; 
but from continued experiments carried on by Professor Rangel, all 




PLATE II. Queensland Fruit Ply (lephritu tryoni). 

1, the fly enlarged; 2 section of apple infested by maggots, natural size; 3, maggot, enlarged; 
4 pupa, enlarged; 5, the fly in the act of depositing eggs in the apple, enlarged. (Uedrawn from 
the Town and County Journal, of New South Wales.) a>Yii num 

2— TL 



18 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 



doubt upon this point has been removed and it is now certain that the 
guava is attacked by both species. 

The Larvte of Trypeta ludens assume the color of their food plant, and 
in the orange are deep yellow, while in the sweet lime and guava they 
are much lighter in color. It is owing to this fact that it is sometimes 




Fig. 3. Trypeta acidtisa. 
Puparium at right, adult at left, greatly enlarged. (After Howard.) 




Fig. 4. Ceratitis capitta. 
o, adult fly; h, head of the same from front; c, spatula-like hair from face of 
male; d, antenna?; e, larva; /, anal segment of same; g, head of same; a and e 
enlarged; b, g, and / greatly enlarged; c and d still more enlarged. (Redrawn 
from Insect Life, by tloward.) 



difficult to discover the small larvse in the fruit. As the larvjt increase 
in size, the condition of the fruit is sufficient to indicate their presence. 
A report of the Commission of Parasitologia states that the Trypeta 
ludens, after completing its larval stages in the fruit, passes into the 
pupa in the ground, and pup£e were bred out under glass in the City of 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 19 

Mexico, remaining in pupal form for from thirty to forty-six days. In 
the warmer and moister soils of the tropics the insect passes through 
the period of transformation in from seventeen to twenty-five days. 

The average life cycle of the insect covers a period of three months, 
making four generations in the year. There is, however, no sharply 
defined season between the broods, but their appearance is continuous. 
The earlier-appearing tlies attack the late oranges, which are ripening 
in the vicinity of Yautepec in April or May. Later, or during the 
period that there are no ripening oranges, they confine themselves 
wholly to the mango and guava, fromVhich they spread again to the 
oranges as they are ripening in November and December. 

Professor Herrera has made a curious calculation as to the possibility 
of infestation from a single female fly. He says: 

By way of. estimating the possible descendants of a single progenitor, we made a 
microscopical examination of the abdominal contents of a female fly, and counted sev- 
enty eggs. Supposing that all of these would hatch, and that the males and females 
were equally divided, each pair in turn would jsroduce seventy descendants, which 
would be 2,450 for the second generation and 85,750 for the third, which would be in about 
nine or ten months. We have found the following coefficients very useful in practice, 
but it should be borne in mind that not all eggs or larvse become Hies. 

To ascertain the number of the first generation in three months, multiply the number 
of parent insects by 35, the second generation by 1,225, and the third by 42,875. For 
example, from 3,000 larvse received from Professor Rangel, there would be 105,000 of 
the first generation, 3,675,000 in the second, and 128,625,000 in the third, after a period 
of nine to ten months. 

To ascertain the coefficient correspondence of each generation multiply by .35, as 
follows : 

Second generation 35X35= 1,225 

Third generation 1,225X35= 42,875 

Fourth generation 42,875X35 = 1,500,625 

This means that the descendants of the 3,000 larvse at the fourth generation, or inside 
of one year, would amount to 3,000 X 1,500,625 = 4,501,875,000. 

One great circumstance which prevents the plague from spreading is the fact that 
the greater part of the wormy fruit is exported to distant places where, for many 
reasons, it can not transform from the larva and perishes before it reaches the perfect 
stage. But should it happen some year that exportation were suspended on account of 
inci-ease of duty or by an interruption in the means of communication, then it might 
happen that all of the fruit in the State of Morelos would be attacked and also that of 
the immediate states, and not only would the orange be lost, but also the mango, guava, 
and other wild and cultivated fruits. Thus the descendants of 3,500 larvae received at 
this office and preserved in alcohol would be sufficient to infest 1,020,377,000 oranges, 
allowing five larvse to each orange. 

What is deduced from these calculations is that were the plague exterminated in 
any locality, and but a single pair of insects had been overlooked, this would be suffi- 
cient to rapidly infest the country again. 

From information received from the State of Morelos a great deal of loss is suffered 
from the plague each year, and this loss is uniform each season, modified only by varia- 
tions of slight importance. 

In Cuernavaca hardly .$1,000 worth of mangoes can be gathered free from the pest, 
although the total production is at least five times that amount. The orange can not 
be grown here on account of the worms. 

Mr. Guillermo Gandara informs us that in a great many of the orchards at Cuernavaca 
the plague has spread to such an extent that the owners have been compelled to discard 



20 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

the cultivation of mango trees, or if they desire this fruit they gatlier it when green and 
place it between plantain leaves to ripen. In this district in a few days Mr. de la 
Barreda collected and destroyed by burning between seven and eight thousand mangoes, 
all of which were infested. Professor Rangel removed over 3,000 larvte from mangoes in 
Yautepec, and destroyed over 57,000 in which the worm was known to exist. According 
to a statenient made at an assembly of agriculturists at Yautepec in February, 1900, the 
loss of fruit from this source alone in this district is from 33 to 40 per cent, or over 
$20,000. 

Even these large losses will fall below the reality, for they do not include the fruit 
which drops from the tree during the year all through the State of Morelos. 

DISTRIBUTION. 

In the course of my investigations, I entered Mexico on the line of 
the Mexican Central Railroad and purchased a large number of oranges 
at the various stations along its whole length. I could not ascertain 
where these were grown, but as few oranges are produced in Chihuahua, 
Durango, or the other States through which this line runs, they were 
probably grown in Sonora, which is one of the principal orange- 
producing sections Of the Republic. The crop in this section was at 
its height, and I had good facilities for making my examination; but 
in several hundred oranges examined, I found no signs of infestation. 
I had the same experience in all my investigations in the higher lands, 
or the tierra templada of Mexico. 

In the State of Morelos, however, the worm is a very serious pest. 
Yautepec, in this State, is the largest orange-producing section of the 
Republic. It lies wholly within the tropics, and it was from this point 
that the plague was first reported. Here the orange and the mango 
grow in juxtaposition, and both are very seriously infested by the 
orange worm, which is also found in the sweet limes. The orange 
season is earlier here than in the tierra templadn or highlands, the 
fruit ripening in November and December. The great bulk of this crop 
was therefore off the trees at the time of my arrival, but I found suffi- 
cient evidence to show that the pest is a very serious one and does great 
damage to the crop. It is here that the Mexican Government has been 
carrying on extensive operations looking to the subjugation of the 
plague, and a force of twelve men, operating under two superintendents, 
has been kept continuously at work by the Commission of Parasitologia, 
experimenting with various expedients to check or destroy the pest. 

I also found the pest in other parts of tropical Mexico — at Orizaba, 
Cordova, and other points in the State of Vera Cruz. I also learned of 
its presence in most of the tropical sections of Mexico. 

During my investigations I made inquiries of many Americans whom 
I met as to the prevalence of the plague, and the result of these inquiries 
was to the effect that the fruit offered in the City of Mexico and along 
the lines of the railroads in November and December was often infested 
with worms, and sometimes very badly infested; that later in the sea- 




Orchard at Yautepec, Morelos. 




(Jieliaid al Jalapa, Vera Cruz. 
PLATE III. Orange Orchards in the Infested Districts. 



22 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

son the fruit was free, and that this season the oranges had been more 
than usually free from infestation. This largely bore out my own 
investigations, as all the fruit which I inspected in March and April 
was free from worms, except the few specimens which I found in the 
tropics, and which were the remains of the old crop. 

Mr. Albert Koebele some years ago made an investigation into this 
matter during a trip to Mexico, and he informs me that he found the 
Trypeta ludens only in the tropical sections, the tierra caliente, and from 
his investigations at that time he came to the conclusion that it did 
not exist in the orchards of the higher lands. Dr. L. 0. Howard, Chief 
Entomologist of the Department of Agriculture at Washington, D. C, 
bears out the statement of Mr. Koebele, and assures me that in his 
investigations, made several years since in the State of Sonora and 
portions of the high plateau, he did not find the worm, and it is his 
opinion that as yet its ravages are confined to the tropical sections of 
the country. 

Infested fruit has been found at various times at points along the 
line of the Mexican Central Railroad, and even in shipments made 
from the Mexican groves into the United States, and has been quite 
common in the City of Mexico, but there is no evidence that this fruit 
was produced near the places where it was found; in fact, oranges are 
not grown to any extent along the line of the Mexican Central, north 
of the City of Mexico, and this infested fruit was, in all probability, 
grown in and shipped from the State of Morelos, the central point of 
infestation of the Republic. This supposition is strengthened by the 
fact that infested fruit has been found during the months of November 
and December, the time at which the Morelos fruit is ripe and being 
shipped. 

Another thing that would seem to indicate that the State of Morelos is 
responsible for the greater part of the infested fruit is the fact that my 
inquiries of Americans in the City of Mexico about the prevalence of 
wormy fruit there were all met with the statement that during the past 
season the fruit was much freer from the plague than in former years. 
This may be accounted for by the energetic action which the Commis- 
sion of Parasitologia has taken to stamp out the pest during the past 
year, and the decreasing amount of wormy fruit in the market would 
indicate that Morelos was the point from which it was shipped. 

My attention was called to another fact by Mr. A. V. Temple, Indus- 
trial Agent of the Mexican Central Railroad. Mr. Temple has spent 
over thirty years in Mexico, and his duties have led him to make close 
observation of everything which had bearing on the business of his 
company. He is also a practical horticulturist and farmer. He 
informed me that he had been acquainted with the orange pest and its 
work for some years past, and had noted that it was not found except 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 23 

in the vicinity of mango trees, and tliat where there were no mango trees 
near the orange orchards there were no worms in the oranges. What there 
is in this statement I am not prepared to admit, but from my own inves- 
tigations I am assured that the Trypeta ludens is primarily a pest of the 
mango, which it leaves to attack the orange at the time the latter fruit 
is ripening. The mango is a tropical tree and is not found in the higher 
Mexican plateaus, while in the tierra cUliente the mango and the orange 
are always found in close proximity. Whether the Trypeta htdens 
would continue its ravages upon the orange if removed from the vicinity 
of the mango is still an open question, but if it should be true that it 
will not, it would remove from us a serious danger. 

Ii:^ relation to his investigations into the spread of the Trypeta ludens 
on the Pacific coast of Mexico, Dr. L. 0. Howard says: 

During April, 1898, the writer visited Guaymas, San Jos^ de Guaymas, and Hermo- 
sillo, Sonora. In the course of this journey he satisfied himself beyond a reasonable 
doubt that Tri/peta hidem has not yet made its appearance in the orange-growing regions 
of the State of Sonora, so that there need be no fear, for the present at least, of the 
introduction of this destructive insect into California in Sonora oranges. 

From the investigations made and the best information obtainable, 
it appears that the pest exists in the States of Guerrero, Morelos, Oaxaca, 
Tabasco, Tamaulipas, and Vera Cruz, and quite probably, also, in Cam- 
peachy, Tlaxacala, and Yucatan. It may also exist in some portions 
of Jalisco, Puebla, and Tepic, although it has not been reported from 
these States. The other Mexican States are so far apparently free from 
the pest. The infested section from which California would have most 
to fear is the State of Guerrero, as its port of Acapulco is one of the 
principal shipping points in Mexico, and there is continuous intercom- 
munication between it and California points. From the States of Vera 
Cruz and Tamaulipas, on the Gulf of Mexico, no fruit reaches Califor- 
nia, but the greater part shipped from there is sent by sea from the cities 
of Vera Cruz and Tampico and finds its way to the Eastern market via 
New Orleans. Oranges from Morelos, the worst infested section of 
Mexico, find their way in the season along the line of the Mexican Cen- 
tral Railroad and might enter the United States through El Paso, and 
there is a slight possibility of their entry through this channel, but it 
is hoped that the strenuous efforts now being put forth by the Mexican 
Government to check the plague in this section will have good results 
and reduce even this danger to its smallest fraction and guarantee our 
growers immunity from even the apprehension of danger. From other 
infested, or possibly infested. States no fruit is shipped, as they are 
either too remote from railroad or sea transportation facilities to reach 
the market, or have not taken up orange-growing as a commercial prop- 
osition. 

In all probability Trypeta ludens is a tropical insect, and, so far, its 



24 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

ravages are apparently confined to the tropical sections, as it has not 
been reported from any orchards in the higher and cooler portions of 
Mexico, the infested fruit found in the markets of these sections being 
shipped from the lower country. Professor Herrera, who has given this 
pest a great deal of study, is of the opinion that it is of South American 
origin and has followed the tropics up until it has reached its northern 
limit in Mexico. This vieAV is concurred in by Mr. Koebele, and in the 
absence of positive information on the subject, Dr. Howard is inclined 
to favor the theory. 

Being a tropical insect it is claimed by the Mexicans that it will not 
endure the low temperature which sometimes obtains in California, and 
Professor Herrera states that from experiments carried on by him he 
has demonstrated that at a temperature of 37° the fly will become dor- 
mant, and will perish with a still lower temperature. At Yautepec, the 
orange section of Morelos, thermometric readings kept for many years 
show the lowest temperature to have been 46°, and the highest 86° in 
the shade, and 117° in the sun. A fall of the temperature to 43° is very 
exceptional, and at this temperature the flies become dormant and 
incapable of action. Whatever there may be in this claim, the fact 
that worms have been found alive in Mexican oranges as far north as 
Chicago in the winter season would seem to prove that, protected by the 
pulp of the orange, the larv?e are able to stand a degree of cold very 
much below that given as the extreme for the perfect insect. The 
experiments made by Professors Johnson and Bruner in breeding out 
the fly from infested fruit in the latitudes of Chicago and Washington 
in the midwinter months of January and February would seem to 
indicate that the insect will pass through its changes at a very low 
temperature. We have no means of knowing at what temperature the 
breeding cases, in which the insects were confined, were kept, but it is 
probable that in the sections where they were it fell below 37°. 

It is also claimed that, being a tropical insect, it will not endure in 
California, and in proof of this statement the fact is pointed out that 
while the insect has been known in the tropical sections of Mexico long 
prior to 1873, when it was first described by Loew, it has never spread 
beyond the tropics. No case of it has ever been reported from the 
plateaus, and no orchards in the tierrd templadn have ever been infested 
by it. It was also pointed out that, although there had been no 
restriction on the importation of Mexican oranges into New Orleans or 
Florida, the pest has never become established in the latter State, or in 
any of the groves of the Southern States. Past experience with tropical 
insects, however, goes to show that it is not always safe to rely upon 
their inability to withstand a climate differing from their natural 
habitat, and it sometimes happens that an introduced species finds 
superior advantages in a new country and becomes even a worse pest 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 25 

than in its native habitat. Some of the more serious of our introduced 
pests have originated in the tropics, a striking instance being the 
Diaspis amygdali^ which has adapted itself to the Eastern climate and 
become one of the most serious of the scale insect pests, attacking all 
varieties of trees of the plum family and withstanding a zero temperature. 
In his report on the pest in Mexico, Professor Herrera says: 

From all inforniation obtained up to the present writing, it appears that the plague 
is found in the warm sections of the south, which forms the center of its distribution. 
It is especially abundant in Yautepec and Cuernavaca (State of Morelos) and the 
•country immediatelj^ surrounding. According to information obtained by 0. W. Bar- 
rett, at one time commissioned under this department to study this subject, the Trypeta 
liidens does not exist, nor ever has existed, in the State of Jalisco, although Mr. Town- 
send has erroneously stated that the plague exists in the whole Republic. Supple- 
menting Mr. Barrett's statement, we have examined large qiiantities of oranges from 
Jalisco and have never found them infested. 

It is probable that Mr. Townsend was misled by purchasing infested oranges in the 
markets, which had been produced in the State of Morelos or other southern points. 

With regard to the probability of oranges being contaminated throughout the whole 
Hepublic because it abounds in the guava, we will state that there is a relative danger 
and that every means should be taken to destroy the pest where it exists. 

The Commission of Parasitologia, under the direction of its chief, 
Prof. A. L. Herrera, has made an exhaustive study of the Trypeta ludens, 
and embodied the result of its observations in a bulletin, from which 
we translate the following: 

California papers assert that should the orange pest succeed in entering California it 
would undoubtedly be practically the ruin of the citrus industry. 

This is an exaggeration. In the regions of Yautepec and Cuernavaca, where climatic 
conditions are most favorable, from $30,000 to 1^32,000 of uninjured fruit are produced 
annually. In Jalapa, where the orchards are well cared for, while the pest is found in 
the guava it is rare in the orange. 

It is further stated in the California papers that between 1881 and 1887 the worm 
plague has spread to all districts in the Mexican Republic where oranges are pro- 
duced. Nothing could be more inexact than this statement, as the following will prove : 

From experiments made by us, we assert that there is no danger of the orange fly 
becoming acclimated in California, and we also assert that it would not exist in a cool 
climate, or where orchards are properly cared for and kept clean. A tropical climate 
like that of Yautepec is required by them, and removed from it there is no danger of 
their ever becoming a plague. 

Trypeta ludens produced in the City of Mexico from pupre gathered at Yautepec do 
not reproduce, nor sting the oranges on which they were confined under mosquito 
netting. In the warmer and more even climate of Yautepec they are very active, and 
lay their eggs in the fruit, even in shaded locations. 

Upon the action of the State Board of Horticulture prohibiting the 
entrance of Mexican oranges into California becoming known in Mexico, 
a strong effort was made to ascertain how widespread the pest was, in 
order that means might be taken to prevent its spread into new sections, 
and to extirpate it, if possible, in those parts where it was established. 
In accordance with this plan the Secretary of the Department of Fo- 
mento issued a letter to the governors of the different Mexican States 
and the agents of the departments, as follows: 

It has come to the knowledge of this department that the State Board of Horticulture 



26 REPORT ON THE TRYPETA LIJDENS IN MEXICO. 

of California lias put in operation a measure prohibiting the importation of Mexican 
oranges into California, under the pretext that the orange worm would spread to the 
orange orchards of tliat State. 

In order that this department may be in possession of all the facts in the case, and to 
enable it to take such action as will advance and protect the interests of our agricul- 
turists, I wish you to give us circumstantial information as to the actual state of the 
plague and the possibilitv of extirpating it. 

Mexico, October 21, i;)03. 

In response to this, many of the governors of the different Mexican 
States instituted inquiries and forwarded their reports, from which we 
have transLated the following extracts. In addition, the agents of the 
Commission of Parasitologia were also instructed to make special reports 
on the orange plague in the various districts. How far these reports 
are absolutely accurate we are unable to state, as the investigations in 
many cases were made by untrained and unscientific men, interested in 
making the best report possible, but it is probable that most of them 
are correct, inasmuch as it was to the interest of the Mexican Govern- 
ment to secure true reports, in view of their efforts to control the pest. 

Aguascalientes. 

I have the honor to reply to your favor of December 16, and would state that the 

plague commonly known as the orange worm is not known in this State, nor is there any 

other which is prejudicial to the orange. 

Alejandro Vazquez de Mercado. 

Chihuahua. 

Replying to your inquiry as to whether the orange worm is found in this State, I 
would reply that our oranges are not affected, but, on the contrary, are of good quality 

and sent into the market free from the pest. 

Enrique Creel. 
Coahuila. 

Replying to your favor of the 15th, requesting information in regard to the orange, I 
would say that the orange is not cultivated in this part of the Federation. 

Miguel Cardenas. 
Colima, 

Colima, December 20, 1904.— I have the honor to inform you that the orange worm 

has not yet appeared in this State. 

E. O. DE la Madrid. 
Jalisco. 

Replying to yours of the 14th of May, 1902, 1 would state that tlie orange plague does 

not exist in this State. 

A. E. Romero. 

La Barca, May 16, 1902.— This office has information to the effect that the oranges in 
this region are entirely free from the plague, and for the encouragement of the growers 
in this locality and the interests of the Republic in general, we have requested the fol- 
lowing large growers to furnish you with proofs of this statement : C. C. Rives Bros. 

and Miguel Flores. 

L. Iguez de la Torre. 

Answering your inquiry of the 15th of May, 1902, 1 take pleasure in informing you 

that in the whole State the orange worm pest does not exist. 

AuRELio DE Martinez. 

Guadalajara, .lanuary 30, 1905.— I have the honor to inform you that the district 
under my command is confined to the municipality of Tizapan el Alto. Orange 
orchards are found here, and I have communicated the contents of your letter relative 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 27 

to the orange maggot to the owners, and they inform me that the Tryj^eta ludens has 

never been found in this locality. 

M. Ahumada. 

Michoacan. 

Repljang to your note of December 15, 1904, I would state that this Government has 
no knowledge of the existence of the Tri/peta ludens. However, for further informa- 
tion we have referred your communication to the section in which the orange is culti- 
vated. 

Louis DE Baldez. 
Nuevo Leon. 

Monterey, January 11, 1905. — Your letter requesting information as to the Tri/peta 
ludens in this State was referred to Manuel G. Rivero, J. A. Robertson, and Arnulfo 
Berlanga, the principal orange-growers of this section, with the request that they sup- 
ply the required information. Answers have been received from them, which, by order 
of the Governor, I respectfully send you, and from which you will see that there are 

no orange worms found in this State. 

Ramon Chavarri. 

After a very careful inspection of this district I have found it impossible to discover 
any indication of the existence of the Trypela ludens here. I made careful inquiries of 
some of the oldest orange-producers, and none of them have ever known of the exist- 
ence of the plague. During my ten years' residence here, during which time I have 
occupied myself in orange culture, I have never seen a worm. I have read full descrip- 
tions of this pest, and have seen it illustrated in the agricultural bulletins of the U. S. 
Department of Agriculture and in those from California. I am acquainted with its 
history and am prepared to find it, but I can positively assure you it has never made its 
appearance here. I have seen it in oranges from the States of Tamaulipas, Vera Cruz, 
and Morelos. I have visited the orange-producing States of Sonora and Jalisco, and in 
neither of these States have seen any indications of the Trypeta ludens. As this pest is 
one of the most dangerous which may affect an orange district, I hope it may never be 
permitted entrance there, for that State is the producer of the finest oranges in the 
world, and is naturally more free than any other section from all orange plagues. 

L. N. Stuart, Administrator. 
San Luis Potosi. 

From investigations carefully made in the districts under my care, I would report 
that up to date there have been no orange worms reported in tliis State. 

F. Mendez. 
Sonora. 

Replying to your favor of the 8th inst., in which you state to the Governor that on 
account of the prohibition of the Mexican orange in the State of California, you will 
visit the orchards of Sonora with an entomologist, named by the Horticultural Board 
of California, I would say that I wish, in order to avoid an unfavorable report, the First 
Magistrate would order the perfect cleaning of all orchards and secure the action of the 
Governor in the matter. I would also ask for a list of all the important orchardists, 
with an estimate of their annual output ; also further information as to insects detri- 
mental to oranges. 

Conformable to the requests made in your note, it is ordered that all orchardists, 
without loss of time, proceed to put their orchards in such shape as to show them in 
their best shape to the commission which will visit them next February. At the same 
time the information and statistics which you desire are being prepared, — as to the best 
orchards in this State, their importance and approximate output. 

Relative to the opinion of the government of this State regarding the California pro- 
hibition of Mexican oranges, I have the honor to inform you that it is a tariff war 
against this fruit, which ripens at the same time as that of California and Florida. 
Therefore, orange-producers in these States, in order to prevent competition with the 
Sonora orange, have obtained from the American Government a duty, excessively high, 
which makes the exportation of the Mexican orange to the United States impossible. 
The problem thus presents two ijhases to the orchardist of Sonora: First, to find a 
market elsewhere than in the United States, or to endeavor to produce an orange 



28 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

earlier than those of Florida and California, similar to that produced in Jalisco, which 
is sold in the American market when there is no California fruit. The demand at the 
same time ijicreases the price to such a figure as to enable the grower to i)ay the 
increased duties and freight. 

Our orange-growers are already beginning to export their fruit to the Canadian mar- 
ket, and there is good reason for hoping that we shall build up a larger demand for 
^onora oranges in that section. 

With regard to getting into the American market ahead of California and Florida, I 
would state that growers in the vicinity of Hermosillo and elsewhere are now experi- 
menting to produce an earlier orange. 

With regard to the orange worm, it is a satisfaction to me to assure you that we do 
not have it in this State, and therefore property owners who are growing oranges do not 
fear any inspection on that account. 

Alberto Chubillas. 
Hkrmosillo, December, 1904.— Referring to your note of the 14th inst., 1 have the 
honor to inform you that the orange plague is not known in this State. 

Raphael Izabal. 
Tlaxacala. 
Tlaxacala, December 16, 1904.— Replying to your favor of the 14th inst., I would 
■state that the orange is not grown in this State, as the climate is not suitable for it. 

Manuel Loaiza. 
Zacatecas. 
Zacatecas, January, 1905.— Replying to your favor of the 14th inst., I would state that 
in portions of Fresnillo, Juchipila, Jerez, Nochistlan, and Tlaltenango the orange is 
cultivated to a small extent, but is not exported to the United States as the crop is not 
suflRciently abundant, and I would also state that the orange plague is not known in 
this section. 

Eduardo F. Parkhurst. 

REPORTS FROM SPECIAL AGENTS. 

Autland, May 23, 1902.— Replying to your request of the 20th inst., I am pleased. to 
inform you that in the canton under my command there is not now nor ever has been 
an orange worm. 

M. Gonzales Rubio. 

GuARACHiTA (Michoacau), March 2.5, 1902.— Almost all the guavas which ripen from 
July to September, and also the plums, are wormy. This is not the case when they are 
gathered in March and April. At this period the guavas and other fruit are clean. 

E. Arceo. 
Rio Verde (San Luis Potosi), January 12, 1905.— Answering yours of the 13th of 
December, I will state that in this zone we are entirely free from the plague. 

R. T. Yanez. 
Guanajuato, December 23, 1904.— The Tnjjjela ludens was found here in only one 
garden. It was vigorously combatted, was not given time to multiply, and was destroyed. 
Since then I believe no other flies have been found. If the Trupetn is seen later, I will 
notify you. 

Dr. A. DuGEs. 

CONTROL, REMEDIES, AND PREVENTIVES. 

Among the various expedients tried, the following have been found 
successful as a check: 

Incineration. In the worst infested orchards all fruit likely to 
harbor the fly is carefully gathered, including all oranges, mangoes, and 
guavas. Large furnaces have been erected in the district and all this 
fruit, with its contained pests, is destroyed by fire. So thoroughly had 
this work been done that at the time of my visit it was difficult to find 




PLATE IV. 
Incinerating Furnace at Yautepec, Morelos, used for destroying wormy fruit. 



30 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

any ripe fruit in the orchards of Yantepec. The incinerating furnaces 
are of rather large proportions, being about eight feet square and of an 
equal height. The bottom is arranged with a grate, under which the 
fire is built, and the heat soon reduces the fruit and worms to a harm- 
less pile of ashes. 

Burial. Another method of destroying the worms which might have 
existed in the fruit was by burial. In some orchards great pits had 
been dug and the fruit was deposited in these and covered with at least 
two feet of soil, care being taken that it was buried deeply enough to 
prevent any larvse which might have matured and worked their way out 
of the fruit after burial from coming to the surface. I had one of these 
pits opened and found its contents a mass of rotten pulp, in which most 
careful search failed to disclose any worms. All worms which had been 
present when the fruit was interred were reduced with the fruit itself to 
a homogeneous mass, in which there was no sign of life. 

These are the two methods of disposing of the pest in its larval stage, 
and certainly both are very effective, as there is no possibility of the worm, 
if it exists in the fruit, escaping in either case. If any of the worms 
should escape and pass into the pupal stage, another method is resorted 
to to prevent them from attaining the mature or fly state, and that is 

Hand-picking". A large force of peons has been kept at work in all 
the orchards at Yautepec, whose duty it has been to carefully rake over 
the soil under the trees in sections known to be infested, and to search 
carefully through the soil so exposed for any pupae that may be turned 
up. This is a somewhat tedious process, but has proved a very effective 
one, as large quantities of the pupse have been gathered and destroyed 
in this manner and the fly crop largely curtailed by this means. After 
leaving the fruit, when it has attained its growth, the maggot burrows 
one and a half or two inches under ground to pass through its meta- 
morphosis, and always in the soil under the tree in the fruit of which 
it has passed its larval stage. By carefully raking this soil over and 
closely inspecting it the greater part of the puppe can be discovered and 
few will escape. 

Fowls in the Orchard. Should any pupa escape in the search, an 
effort is made to complete the work, and fowls are used as a supple- 
mental agency in the process of extirpation. Movable coops have been 
arranged and these, each with a number of chickens, are moved about 
the infested section and the soil beneath the trees is kept constantly 
raked over and exposed and the chickens find any of the pupae which 
mav have been overlooked. 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 



31 



Insecticides. The warfare on the Trypeta hidens has not, however, 
been confined to the insect in its larval and pupal stages. It has been 
determined that no fly shall escape if the Commission of Parasitologia 




Force of laborL-i> eiiiplus td iii tAiiUieiiiii^ iult-^ted liuil. 




Destruction of infested fruit by fire. 
PLATE v. Destroying Infested Fruit at Morelos. 

can compass its destruction. In the course of many experiments look- 
ing to the control of the Trypetn ludeiis, Mr. Don Jose Betanzos dis- 
covered the usefulness of a common Mexican plant for this purpose. 




PLATE VI. Haplophyton cimicidmm. 
Plant used for poisoning flies of Tn/pela ludens. 
(From the Commission of Panisitologin.) 




PLATE VH- Pi''-'^ "*" 'T'^'^P^'^-'^ LUDENs. 

1 ;„ tiio infested orchards at Yautepcc, Morclos. 
Picked from the ground 111 the initM i , 

(From the Commission of ParasUolog.a.) 



CRATOSPILA RUDIBUNDA 



(PARASITE OF THE ORANGE MAGGOT) 



) 




() 



7 



From Drawing by the Comision de Parasitologia Agricola, Mexico. 



v-^'v \f,i^:v 



CRATOSPILA RUDIBUNDA. 

(Parasite of the Oi-aiise ISfaggot.) 

1 — Female, side view. 

2— Female, dorsal view. 

3 — Female, ventral view. 

4— Male, dorsal view. 

,5— Pupa. 

()— Larva. 

All greatly enlarged. 

7- Female ovipositing on maggot in gnavf 

Very greatly reduced. 



REPORT ON THE TRYPETA LUDENS IN MEXICO, 33 

This plant, of which we publish an illustration, is the Hdplophyton 
cimicidum. An infusion of this herb is prepared and sweetened with 
sugar, and then sprayed on the infested trees. This preparation has also 
been effective in the destruction of house flies. In fighting the Trypeta 
htdens, Professor Rangel obtained very satisfactory results from the use 
of this preparation. The flies absorb the sweetened fluid with avidity, 
and soon become torpid and fall to the ground. Flies so poisoned are 
much agitated, rub themselves all over, stand on their hind legs or hang 
by their front ones until they drop, when they turn over on their backs, 
dead. The preparation is made by boiling about two pounds of the 
herb, cut fine, in three gallons of water, and after the herb is thoroughly 
boiled two pounds of sugar is added, and the whole is strained and used 
as a spray. 

Natural Checks. In Mexico it is claimed that extremes of tempera- 
ture form one of the most important natural checks on the spread of 
this insect, and that it can not endure extremes of either heat or cold, 
a temperature below 37° or above 100° Fahrenheit in the shade being 
fatal to it. We do not know how extensive the observations have been 
upon which this statement is based, but it is probable that the insect is 
kept in check to some extent by extremes of temperature. 

Parasites. An ichneumon fly, the Cratosipila rudihundn, is quite 
common in the sections where the Trypeta ludens is found, and is a very 
material aid in keeping the pest in check. This insect, through some 
instinct which it possesses, is enabled to locate the worm of the Trypeta 
below the surface of the fruit, and, inserting its long ovipositor through 
the outer coating of the fruit, lays its fatal egg in the larva of the fly 
with unerring accuracy. This egg, in its turn, hatches out a worm, but 
within the body of its host, and the unfortunate larva of the Trypeta 
ludens never attains its perfect condition. 

The parasite has not as yet done very effective work on the Trypeta 
ludens, as investigations have shown that not over ten to fifteen per 
cent of the maggots are parasitized. Every effort is being made to 
encourage the propagation of the parasite, and great hopes are enter- 
tained that it may yet overtake the plague and keep it in check. 

The extent of the work done by these various checks is shown in the 
fact that prior to the active work undertaken by the Commission of 
Parasitologia the markets of the City of Mexico and of the northern 
Mexican States were flooded with wormy oranges in November to 
January, and this was so noticeable to visiting Americans that many 
of them forbore to use the fruit for fear of the pest; while inquiry 
among the same class and among fruit merchants of the City of Mexico 
elicited the information that during the past season there was a notice- 
3— TL 



34 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

able diminution of wormy fruit on the market, and in fact little of it 
has been noticed. People of whom I made inquiries relative to the 
prevalence of the pest did not know any reason for its decrease, and 
were satisfied to state that the oranges during the past two seasons 
were not so wormy as they used to be. Whether the efforts of the 
Mexican Government can reduce this pest below the danger limit is an 
open question, but it is certain that no effort on its part is being spared 

to do so. 

While strong efforts have been made in all those sections of Mexico 
where the worm exists to get it under control, the principal work has 
been done at Yautepec as the center of infestation. Here every experi- 
ment looking to the extirpation of the pest has been tried, and the 
Government has used coercive measures where necessary to compel 
fruit-growers to follow the plans outlined for them by the Commission 
of Parasitologia. 

As indicating the method pursued in fighting this plague by the 
Mexican Government, Professor Herrera reports the destruction of fruit 
at Yautepec, in the State of Morelos, for the past three months, as fol- 
lows: March 10th, 10,101 oranges; March 18th, 10,327 oranges. The 
number of mangoes destroyed by fire was, March 25th, 6,137; April 1st, 
3,095; April 5th, 14,98fi; April 13th, 18,942; May 20th, 17,612; May 
27th 40,093; June 3d, 39,218. This was all fruit growing in the infested 
district which was destroyed in order to reach the enclosed larvae. 

It is probable that the Trypeta hi dens is, as stated by the entomolo- 
gists of Mexico, an imported pest; that its country of origin is some 
part of South America; and that, as its food plants have spread along 
the tropical sections of Mexico, it has gradually followed until it has 
become established in tropical Mexico. If this is the case, it is quite 
probable that its natural enemy will yet be found in South America, 
and a more efficient check be obtained for it than now exists. This 
supposition is largely borne out by the fact that Mr. George Compere, 
after searching over a large part of the world to discover the original 
home of the Australian fruit fly, discovered it in Brazil, and there 
found its parasite. It would appear quite likely, therefore, that the 
Trypeta ludens may have originated in the same life zone with its 
Australian relative, and that the natural enemy of both may exist in 
the same section. 

The most efficacious method of controlling this pest, so far, is thorough 
cleanliness in the orchard, and the destruction, by burning or burying, 
of all infested fruit before the larva- leave it for the purpose of pupation 
in the earth. Other methods have been found either impracticable or 
too expensive in large orchards where generations of flies are bred in 
different fruits and during the whole year. 

An inspection of the orchards of Yautepec, made in February, 1900, 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 35 

-convinced the Commission of Parasitologia that the best method of 
controlling the pest would be the total destruction of all kinds of fruit, 
green and ripe, wild and cultivated. Early oranges appear in Yautepec 
in January to April or May. This crop of fruit, if destroyed by fire, 
would cut the cycle of the generations, and the flies produced from the 
pupae in the soil would find no fruit upon which to oviposit, as the 
mango ripens only in July. This process, to be effective, according to 
Professor Herrera, should be general in all southern Mexico, where the 
plague is known to exist; for if the work is confined to one section, 
•even if ever so thoroughly performed, the insect may be reintroduced 
from other infested regions. So the plague should be attacked at the 
saniQ. time in all parts, destroying, if necessary, all oranges and mangoes 
in the infested sections, in order that there may be no spot from which 
the plague may be afterwards disseminated. 

The spread of the pest may be prevented by the gathering of all the 
green fruit before the female fly has deposited her eggs below the rind. 
But if this work is not generally done, enough of the flies will escape to 
give the plague a new start. The guava is a fruit within which the 
fly is generally found, and as this grows wild in many places, it would 
be necessary to destroy this also. 

The pest is bred in and spreads from the fruit which falls on the 
ground and which is allowed to remain there, and while this is left 
undisturbed, neither reduction of transportation rates nor a lower tariff 
will help the orange-growers. It is all in vain so long as the growers 
fail to destroy the fruit which falls and which contains the worm. Even 
with the destruction of the fallen fruit there is danger that some of the 
larvse may leave the fruit still on the tree, and, by reaching the ground, 
find a place of safety for their transformation. This last contingency 
is being made a matter of special study by the commission and its 
agents, and various methods of reaching the pests have been tried. 

HABITS. 

(Translated from bulletin of the Commission of Parasitologia.) 

The Trypeta ludens attacks the sweet orange {Citrus aurantium), 
mango {Mangifera indica), and the guava {Psidium pomerifenun) . 
Worms in mangoes, which we had under observation in April, and 
which were secured in Cuernavaca, transformed into pupa3, and in 
thirty-seven days developed into flies, exactly as did those of the orange. 
One larva passed through its changes without leaving the fruit, while 
another transformed on the surface without entering the soil. 

The worms are very voracious, and in a short time will devour a 
mango or a section of an orange. They are sometimes found in num- 
bers six to eight, nine to ten, or even as many as twenty-four in one 
fruit, the average number being five. It is a provision of nature that 



36 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

the female fly is provided with an instinct which prevents her from 
laying over six to ten eggs in one place, for if she deposited all her 
seventy or more eggs on one fruit, there would be insufticient food for 
the worms. The eggs are laid in clusters, and the female deposits 
them on eight or ten or sometimes more specimens, so that one female 
fly may infest a number of individual fruits. 

The orange worm, like most of those living in liquids, is very hardy 
and withstood for some time immersion in dilute ammonia, acetic acid, 
and feeble solutions of formalin and alcohol. In passing from a sweet 
to a sour orange, or from an orange to a mango or guava, the changed 
conditions did not seem to affect it. Various other experiments — sub- 
mersion in water, electric shocks, etc. — were tried, but without serious 
effect to the worm. 

[In San Francisco a lot of maggots were taken direct from some 
oranges imported from Acapulco, and were placed in undiluted alcohol. 
None of the worms died in less than ten minutes, and some even showed 
signs of life at the expiration of half an hour. Their natural habitat is 
immersion in the juices of the half-ripe fruit, and it is undoubtedly this 
fact which enables them to withstand immersion in stronger fluids for 
so long a time. The experiment in San Francisco therefore bears out 
those of the Commission of Parasitologia in Mexico.] 

As soon as the worm has attained its growth, it leaves the fruit, 
Avhich usually falls, and seeks a spot in which to hide away during the 
period of transformation. In soft soil this is easily done. In some 
instances they remain between the sections of the orange or within the 
guava. In cases where the fruit does not fall from the tree, the worms 
will leave it and drop to the ground, which they penetrate for the pur- 
pose of pupation. 

The orange is always attacked on the under side, and when the fly is 
preparing for oviposition she moves slowly over the fruit as though 
seeking for an appropriate spot. When this is found she quickly 
attaches herself in a perpendicular position and remains quiet for a 
period varying from a few seconds to two minutes. She repeats this 
operation three or four times, w^hen she flies to another fruit and repeats 
the process. 

Professor Rangel experimented with twenty Trypetse which he had 
confined under a mosquito net with some oranges and guavas. One 
female perforated the rind of the guava; all the others preferred the 
oranges. One of the latter perforated the same orange four times and 
another six times, the whole operation requiring half an hour. 

The eggs are deposited by the female in the pulp of the fruit at or 
near the ripening period, and are probably acted upon by the increased 
temperature characterizing that period. Incubation progresses under 
favorable conditions of shelter, moisture, and inaccessibility to ichneu'- 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 37 

mon flies and other parasites, which can not from the outside discover 
the location of the eggs and are unable to penetrate the epidermis in 
search of them. 

ACTUAL CONDITION OF THE PLAGUE. 

(Translated from bulletin of the Commission of Parasitologia.) 

Agents sent to Morelos at the end of July this year (1900) report the 
fly as very rare, but it still exists, and in Yautepec the first generation 
which proceeds from the mango is appearing. In Yautepec there are 
wormy guavas, and Mr. De la Bareda states that on July 23d he visited 
a district in Cuernavaca, where the guava is abundant, and nearly all 
the fruit was infested. 

Almost all of the larvte of the fruit which is exported from the State 
of Morelos perish from one cause or another, or are unable to find suit- 
able conditions under which to pass through their transformation, and 
the flies are very rarely found in the valley of Mexico. Here is one of 
the great reasons why the plague is not more serious. Each season, 
millions of the worms are shipped from Morelos in the fruit, and of all 
these, few attain maturity and none perpetuate themselves. 

On August 10th, Professor Rangel extracted over 4,000 pupae from the 
soil by raking it over and hand-picking. This indicates that a new gen- 
eration of winged insects would soon appear and it is this generation 
which does the worst work on the oranges. 

RULES FOR COMBATING THE PEST. 

The Commission of Parasitologia has formulated the following rules 
for fighting this pest: 

1. Gather each day all mangoes, lemons, and oranges which may have 
fallen from the trees, and deposit them in a clean corner of the orchard. 

2. Destroy all fruit so accumulated at least once a week. 

3. It is preferable to destroy the fruit by burning, but it may be dis- 
posed of by burial, and when buried it should be covered with at least 
fifty centimeters (about 20 ii:iches) of soil. 

4. As the same worm exists in the guava, this fruit should also be 
destroyed in the same manner. 

COMPETITION WITH MEXICAN ORANGES. 

In a bulletin issued by the Connsion de Parasitologia Agricola on the 
Trypcta ludens, under the heading of " Unjust Prohibition of the Mexi- 
can Orange in California," it is stated that, according to circulars 
published by the Ministry of Fomento, the Board of Horticulture of the 
State of California has prohibited the importation of Mexican oranges 



38 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

under the pretext that it might be the means of introducing this 
terrible plague into the orchards of that State. The report continues: 

It is the opinion of tlie most distinguished members of the Agricultural Society of 
Mexico that the California horticulturists have always dreaded competition with our 
fruit, as our more favorable climate causes our oranges to ripen much earlier than theirs 
and gives us the advantage in the American market. 

Our early exports were treated with discredit, as the fruit had been imperfectly 
packed by novices, but these faults were soon corrected, and one would have thought 
that there would have been no more difficulty ; but, far from it, they fought tenaciously 
to impose such high duties as to practically prohibit our orange exports into the United 
States. 

California is not weakening in the crusade she has carried on against the importation 
of our oranges, and she now accomplishes the desired end by barring the entrance of 
Mexican fruit into America. 

This idea is prevalent among a great many of the Mexican growers^ 
and it is openly expressed, in much of the correspondence and many 
publications, that jealousy and fear of Mexican competition- have been 
the main causes for the embargo placed by California upon the Mexican 
fruit. It is asserted that the fruit grown in our sister republic is so 
superior in quality to that grown in California, that there was even 
danger of our oranges being crowded out of our own markets, and that 
to prevent this we had to put an embargo upon the Mexican fruit, using 
the presence of the worm as a mere pretext for our action. A suspicion 
of this kind is not creditable to either nation, and it was my effort to 
remove it by a plain statement of the facts in the case. I assured the 
Mexican authorities that the only reason for our embargo lay in the 
fact that we were not prepared to take the chance of introducing into 
our orange groves a new pest which might prove a very serious one 
should it become established. When the great importance of our citrus 
industry is considered; that it is one of the greatest single sources of 
revenue to our State; that in it are invested millions of dollars of 
capital; that it gives employment to thousands of people, and that even 
a small injury inflicted upon so important an industry might mean 
enormous loss in the gross, it is not necessary for us to seek for an 
empty pretext to care for it. There is nothing farther from the minds 
of California growers than jealousy of their Mexican neighbors, nor do 
they fear anything less than competition from that source. 

That Mexico could grow good oranges is unquestioned; but she does 
not, and it will, under the best conditions, be many years before she can 
possibly compete with the product of California. In the course of my 
investigations I saw some fairly good orchards, but even these would 
not compare with the average of those in California. As a rule, how- 
ever, fruit there is grown by accident. The seed is planted and if it 
grows it is well, equally well if it does not. There are no varieties, for 
all are seedlings; the trees are neither budded nor grafted and show no 
indications of .the care which is bestowed upon them in our State. 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 



39 



Usually they grow without any regularity, mixed with mango, coffee, 
and banana trees, the whole forming a perfect jungle, which would be 
fatal to any growth in our orchards. Being all seedlings, the fruit 




Orchard near Cordova, Vera Cruz. 




Orchard near Jalapa, Vera Cruz. 
PLATE IX. Mexican Orange Orchards, Showing Method of Cultivation. 

varies with every tree, and while some of the oranges are of excellent 
flavor, there is no guarantee that in purchasing fruit you will get two 
specimens of the same quality. No care is taken of the orchards, and 
pruning, cultivating, grading, and other matters which are so carefully 



40 KEPORT ON THE TRYPETA LUDENS IN MEXICO. 

attended to by us are entirely ignored. In the markets of Mexico I saw 
oranges brought in carts over the rough roads, shoveled from the carts 
into baskets, transferred on the backs of peons and dumped in big 
heaps in the wholesale houses, from which places they were distributed 
with no more care. In the whole process they are handled as we han- 
dle so much coal or gravel. There is no uniformity of color, size, or 
quality. 

There is no doubt that Mexico possesses all the requisites of soil, 
climate, and natural conditions for producing good oranges, but so long as 
her growers resort to their present careless or indifferent methods, Califor- 
nia orchardists need have no fear of competition from that source, and the 
statement made that we have used the presence of the Trypeta ludens 
as a mere pretext to prevent the superior Mexican fruit from driving 
ours from the market will strike our growers as puerile. 

The total production of citrus fruits in our State is now from 25,000 
to 30,000 carloads annually. The fruit is carefully grown, picked with 
the greatest care, and handled at all points as tenderly as so many eggs. 
It is assorted and graded, carefully wrapped, and put up in such a way 
as to reach the markets in the most attractive shape and best possible 
condition, and were the markets of the United States thrown wide open 
there would be no chance for the Mexican fruit, grown and handled as 
it is now, to compete with that of (Jalifornia. 

The statement that oranges there come into the market before those 
of California also arises from a misunderstanding of conditions here. 
The orange season in California is continuous. There is no month in 
the year when we can not ship oranges, and when we do not ship them 
to the Eastern markets. The great bulk of our crop is shipped in the 
late winter and early spring months, as the demand is more active at 
that season. 

The fear of the introduction of the Trypeta ludens has not been a 
mere pretext, therefore, to avoid competition with a formidable adver- 
sary, but a dread of a genuine danger which we believed threatened one 
of the great industries of our State. This fact, I believe, has now been 
made clear to the officials of our sister republic, although they still 
regard our fears as somewhat exaggerated. 

That the Trypeta ludenfi is a serious pest in the sections where it is 
established is acknowledged by the Mexican authorities, and they are 
using every possible means to check its spread and also to extir- 
pate it. 

The belief that our action against Mexican oranges is due to jealousy 
and fear of competition is an unfortunate one. It is based on ignorance 
of true conditions, and a broader knowledge of the California orange 
industry will remove it. The Mexican Government respects the precau- 
tions which we have taken for the protection of our fruit, and realizes 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 41 

the fact that they are not prompted by petty motives. At the same time 
there is a prevalent fear that the California embargo may become general 
and that the Mexican fruit will be prevented from entering the United 
States. To remove any possible cause for snch embargo the Mexican 
Government has left no stone unturned, and no expedient which would 
keep the orange pest in check has been left untried. If the pest can 
not be exterminated it will at least be kept in check and any danger 
from its introduction be reduced to a minimum. 

As indicating the sentiment of Mexican growers and Mexican jour- 
nals, we translate the following: 

"El Agricola" publishes the following under the heading "The 
Mexfcan Orange" : 

The embargo placed u])on the importation of ISIexican oranges is a liard blow at one 
of the most important of our products. The motive that California alleges is that 
worms in our oranges might propagate and invade their orchards and seriously inter- 
fere with their great production of fruit. 

This movement may at first appear to be justified, but if we consider the strong oppo- 
sition which California has made to our oranges from the first day of our appearance in 
their market, it is easy to understand that there is another reason for the American 
producers to maintain the prohibition. 

Although our first fruit exportations were small, they were sufficient to prove to our 
neighbors that Mexico, with her incomparable climate, and enjoying an era of pros- 
perity and peace, would soon become an important factor in the world's market with 
the products of her soil ; that this humble beginning in the shipment of oranges would, 
in a short time, increase to great proportions, and as they could defy commercial com- 
petition with the whole world, they feared that our fruit, which a more propitious 
climate ripens a few months sooner, would be the earliest in the nuirket. In the begin- 
ning they regarded our shix>ments as trifling, and, owing to poor packing, as unworthy 
of consideration, but we promptly corrected this error and hoped that there would be 
no more ditliculty. Far from leaving us in peace, however, California insisted that 
high duties be imposed upon the Mexican fruit, and this was practically equivalent to 
an embargo jjlaced upon all our fruits in the American market. We do not deny the 
existence of wormy oranges in Mexico, but these are found only in the State of Morelos, 
and it seems that a resolution which so seriously injures us should have been limited in 
its execution to the infested district. We suppose that the Americans, so much ahead 
in everything, have means of recognizing tlie damaged oranges from the others, so 
that they could destroy the bad and admit the others. 

To avoid this danger we should take some measures, upon which we shall sjieak 
more fully in another issue. 

The following appeared in " El Progreso de JNIexico " under the head- 
ing of " Exportation of Mexican Oranges": 

We read in one of the city papers: " The Mexican orange has obtained the preference 
•over that of California. This orange has been exported principally from the frontier, 
but the railroad from Cuernavaca unites Morelos with the nation's capital, and thus the 
iruit may easily be sold in the great centers." 

It is lamentable that some of our contemporaries are spreading errors like that con- 
tained in the above. It is false that the United States prefer our oranges to theirs. The 
fact is they only purchase ours when they are unable to get those of their own growing. 
We should not forget that the American orange is actually superior to ours. We say 
this because we can, with proper care, produce as good, or better, oranges than those of 
either California or Florida. The first great requisite for an agricultxirist as well as for 
a mechanic is to know exactly the (jualities and defects of his products. It is the only 



42 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

way to become superior to his competitors. Jt is better, in the present case, to frankl>^ 
confess that we are inferior to the American orange-growers, and then take all measures- 
to change this state of things. 

In regard to the oranges produced in the State of Morelos we have said a hundred 
times, and everybody knows it, that they are wormy. They know this in the United 
States. The California producers, who appreciate the strong competition which we may 
maintain with them, do not hesitate to make this known. The day that a carload of 
Mexican oranges arrives in the United States, it will be detained at the border and prob- 
ably destroyed. The California horticulturists will then repeat their song, "All Mex- 
ican oranges are wormy." The exportation of oranges from Morelos is practically 
imjiossible. It will do no good to the producers of tliat State, and will cause prejudice 
to the other productive regions of the Republic. 

The bulletin of the Agricultural Society of Mexico, October 17, 1900,. 
has the following to nay regarding the orange worm and its work: 

For some time past attempts have been made, under various pretexts, to exclude 
Mexican oranges from American markets, the orchardists of California objecting ta 
competition with our fruit. 

The strongest reason so far advanced for this course is that there is a worm in our 
fruit, and that it might affect their oranges. Since the embargo which was placed 
upon Mexican oranges by California went into effect, our Government has taken a great 
deal of pains to ascertain the extent and amount of dantage done by the orange worm 
in the Republic of Mexico. From its investigations it appears that the worms which 
the Californians dread so much are only found in the State of Morelos, and that there is- 
no reason for the prohibiting of Mexican oranges whatever. Our Government has taken 
various measures to coiTibat the plague, and experimented with various processes. It 
has ordered the destruction of all infested fruit, and recommended the greatest cleanli- 
ness in the orchards in order to prevent the reproduction of the pest. Through these 
experiments on the part of the Department of Parasitologia, the important fact has been 
estabhshed that the worm which attacks the guava, and is found in Jalapa, Coatepec, 
and other places, is all of the same species, and if the orchards are kept clean the worms 
will not attack the fruit. This should be a strong argument to prove that California 
need not apprehend the introduction of this pest, as their orchards yre always kept 
very clean. 

The bulletin of the Agricultural Society of Mexico of the 30th of 

November, 1896, published the following from the International Bureau 

of Information at El Paso: 

Commercial circulars here incline to the belief that Mexico is designed to become a 
formidable competitor of California, Florida, and Italy as a producer of oranges. The 
Mexican grower can now export his products with facility, thanks to the railroads- 
which unite this country with the United States. Land in Mexico is cheaper, as also i.s 
labor, and Mexico can produce oranges enough to supply American markets and realize 
good profits even though selling them at lower prices than those of California and 
Florida. 

A bulletin of the Agricultural Society of Mexico, dated June 30, 1897,, 
has the following in regard to Mexican oranges: 

From early days in their histories, New York, Phihidelphia, Boston, and other 
prominent cities of the United States have been importing large quantities of oranges 
from Central Aiiierica, the Antilles, Italy, and Valencia. Tlie railroads connecting the 
United States with Mexico were not finished when, in 1880 and 1882, some enterprising 
individuals with a little capital endeavored to introduce oranges from Mexico direct to 
the United States. At the present time the exportation is considerable. The fruit 
reaches the United States through El Paso, Nogales, and Laredo, and so favorably has our 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 43 

fruit been received tliat in uiiuiy markets of the United States it has entirely supplanted 
not only the foreign, but also fruit from California and Florida. The very name of 
Mexican oranges became a guarantee of their quality, and so favorably were they known 
that peddlers cried them as "sweet Mexican oranges." From these facts it is not sur- 
prising that orange culture in Mexico has received a great deal of attention among the 
agriculturists, which is only equaled by that of coffee culture. The production of oranges 
at the present time is insufficient to supply the demand, as may be seen from the follow- 
ing table* showing the quantity produced, together with the value in Mexican coin, in 
each State and Territory of the Republic : 

State. Number. Vhlue. 

Aguascalientes 178,000 |850 

Campeachy 158,000 136 

Colima 4,418,000 .5,830 

Chiapas 4,737,000 10,.345 

Chihuahua -. 694,000 6,580 

Durango 3,396,000 15,950 

Guanajuato 1,051,000 3,727 

Guerrero 814,000 2,344 

Hidalgo 179,000 408 

Jalisco __- 14,951,000 145,100 

Michoacan 25,020,000 93,668 

Morelos 5,160,000 42,1.34 

Nuevo Leon 13,820,000 62,0.30 

Oaxaca 13,110,000 43,786 

Puebla 6,133,000 2,455 

San Luis Potosi 33,270,000 110,562 

Sinaloa 3,327,000 23,020 

Sonora 28,625,000 241,425 

Tabasco 446,000 998 

Tamaulipas 4,1.50,000 7,350 

Territorio de la Baja California 3,852,000 12,740 

Tepic 650,000 2,583 

Vera Cruz . 4,125,000 13,996 

The data of this tal)le are not all correct, but give a general idea of the importance 
which the production of this fruit has acquired. The State of Vera Cruz, for instance, 
produces a greater quantity than either Morelos or Puebla. This production will cer- 
tainly increase and in a few years will exceed that of California, which has created so 
many fortunes. This year (1897) oranges have been sold in Yautepec from .$6 to .|8.75 per 
thousand ; in La Barca, in the State of Guadalajara, from .$10 to|15; in Hermosillo, from 
$10 to $20. To estinuite the profit of this business, it may be stated that in Chicago, 
Kansas City, St. Louis, and Cincinnati, Mexican oranges are sold from 50 cents to $3.50' 
(American gold) per box, which contains from 176 to 200 oranges. These having been 
bought in Mexico for from .$6 to $8 per thousand (Mexican money), it is easy to estimate 
the profit in the business, as the packing and shipping expense is trifling. When the 
producers market their own fruit instead of selling it to outside dealers who are now 
appropriating the greatest profits, this branch of fruit-growing will prove very profitable. 

*The tigures given in the above table represent the number of oranges produced, as 
oranges are sold by the thousand, and the value is in Mexican money, which represents, 
one-half the value in American coin. Fruit conditions in Mexico are practically the 
same at present as when this was published. 



44 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

CORRESPONDENCE. 

The following correspondence passed between the members of the 
commission for the investigation of the Trypela hidenu, and formed part 
of the report made to, his government l)y Professor Herrera: 

Mexico City, March 25, 1905. 
J. Isaac, Esq., Delegate of the Commission of Jlorticvlture for the Stiidj/ of the Orange 
Plague — Present : 
Dear Sir: Wishing to present to the Department of Fomento the following report, 
I beg to be allowed to submit to you some cj[uestions and to consult you on some 
points still doubtful and relative to our commission, in the hope that, if not incon- 
venient, you will kindly answer me in writing, so that I may have a clear and exact 
knowledge of your valuable opinion and thus be able to present it to the Department 
of Fomento. 

First — I wish to know whether you desire to visit any or all the places of the Mexican 
Republic where the orange is grown, besides those you have already seen, in order to 
get at once the necessary transportation on the railroads, and also that I can prepare 
everything that may be convenient to be able to accompany you, without any restriction 
whatever as to the jjlaces, climates, or duration of the explorations. In fact, I wish you 
to be perfectly satisfied in every point, and I shall be very much pleased to have the 
honor of accompanying you and thus enjoy your instructive and worthy society and 
profit thereby. 

Second — I give you the heartiest thanks for the earnestness you have manifested in 
these studies and explorations and also for the kindness and deference you have shown 
me. However, I should be very thankful to you if you would tell me, in all frankness, 
whether there is anything wherein I did not give you all satisfaction that you wish and 
it is my desire to give you, as it is also the order of my superior; it might have hap- 
pened that, owing to my ignorance of the English language, or through inadvertence, I 
have not attended at once to some of your suggestions and observations. 

Third — It is believed that the horticulturists of California have established the quar- 
antine against our orange, taking as a pretext the danger of the plague, but, really, to 
avoid a competition which, as it is said, would be very prejudicial to them, because our 
oranges are better flavored and earlier than those of California. You have kindly given 
me some reasons which I would like you to indicate in your answer, because they would 
put an end to such suppositions. 

According to the "Carpologia," of Barcena, the following are the dates at which the 
orange crop is produced : 

Place. Date of Ripening. Value, Mexican. 

Atotonilco el Alto November to May .til, 800 

Ario (Michoacan) September to March 2,000 

Yautepec October to December 36,000 

Montemorelos (Nuevo Leon) October to February . 

Tancanhuitz (San Luis Potosi). September to December 50,000 

Rio Verde (San Luis Potosi) October to March 12,630 

Hermosillo October to February 15,000 

Guaymas(Sonora) December to February 7,000 

Comondu (Lower California). October to December 6,600 

Santiago Huatusco (Cordova). __ October and November 2,500 

Fourth — It is reported that the Sonora orange has been prohibited, if not in Cali- 
fornia, at least at some points on the Arizona railroad, for the commercial convenience 
of the horticulturists and railroad people 'of California. 

However, such an assertion has been refuted by information sent to the sub-secretary 
of Fomento, Hon. Andres Aldasoro, by Mr. S. Camacho, as well as by the official 
reports from the Sonora Government. Even in 1897 Dr. L. 0. Howard wrote in the 
Yearbook of the Department of Agriculture at Washington that the Tri/peln hidens does 
not exist in the Sonora orange. 

On another part, the oranges proceeding from Mexican points have been rejected and 
<lenied admission. At least so says a circular published by the Department of Fomento, 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 45 

and, I believe, to be short, that till these difficulties arose from the fact that the worm 
was found in some shipments of oranges from Acapulco, which is an infested place, as 
are many others in the tierra calienfe, but whose production is insignificant. 

Fifth — Mr. Craw saj^s that the traffic agents of the Southern Pacific Railroad have 
rejected some shipments of Mexican oranges, and that, in fact, no tariff has been 
established on oranges between Mexico and California in order not to cause any 
prejudice to that important fruit industry of California. " The cars used for the trans- 
portation of Mexican oranges to the Western States, as I have been told by the agents, 
are disinfected by steam as soon as they are unloaded, in order to kill the worms or 
nymphs that they may contain. This was done also last year, in accordance with an 
order fi'om the Commission of Horticulture." (Report on quarantine. May 15, 1901.) 

I truly believe that much of all this is the result of the false or exaggerated reports 
given by the press and the inconsiderate and generally exaggerated information sent by 
the commercial and express agents who may have definite and certain ideas about com- 
mercial matters, but who do not know sufficiently the plague we speak of, or who accept 
without any proof the information given by the ti-aders or the newspapers. It should 
be part of our duty to make the necessary correction. 

Sixth — In oi'der to duly prove the absence of the Trijpeta ludens in certain parts of the 
Republic, I offer to forward you branches of orange trees in full fruit-bearing state, 
which could, if there is no inconvenience, be examined in the office of the Quarantine 
Officer in California, thus giving you the assurance that the fruit has not been selected. 
Those remittals would be made regularly through the Department of Fomento. 

I consider as very important that this (juestion should be settled, because not even 
two years of continuous traveling at heavy expense would enable us to visit all the 
orange-producing regions of the Mexican Republic, as they extend from Sonora to 
Yucatan. It might be objected that we have visited the orchards during the month of 
March when the orange trees do not bear any fruit, and therefore that our reports can 
not give any security about the non-existence of the plague, which might be latent. 

As the time would pass away, after three or four years, it might be argued that our 
explorations and proofs were already old and that the plague might have invaded new 
territory where heretofore it had been unknown. The experience acquired in that kind 
of work clearly shows that nothing good and definite can be obtained unless it be 
through constancy and a certain degree of tenacity which will lead sooner or later to a 
result that may challenge any attack. 
Again thanking you sincerely, I remain. 

Respectfully yours, 

(Signed:) A. L. HERRERA. 

P. S. — I herewith send you a copy of the letter lately addressed to Mr. Aldasoro and 
referring to the prohibition on the orange from California. 

Mexico City, February 3, 1905. 
Hon. Andres Aldasoro, Sub-Secretary of Fomento, Mexico City: 

Dear Sir AND Friend: Confirming the contents of my letter of January 28th last, I 
have the honor to communicate to you the information which, on the 3d of the present 
month, Mr. J. A. Nougle, assistant general manager of the Sonora railroad, sent me in 
answer to my letter of January 28th. 

" I hereby acknowledge the receipt of your favor of January 28th, wherein you com- 
municated to me the letter sent to you by the Honorable Sub-Secretary of Fomento, 
about the law promulgated by the Department of Horticulture of California and the 
damage that may have been caused to our company by the same, prohibiting the impor- 
tation of the Mexican orange into California. 

"You may assure that honorable functionary that the mentioned law has caused no 
prejudice to us, because up to the present day nothing has been found to be said against 
the splendid Sonora orange, either in California or elsewhere. 

"The only misfortune suffered by the growers and exporters of oranges in the State, 
and consequently by us, is that since the promulgation of the so-called Dingley Law, in 
force since July 24, 1897, the exportation of the orange to the United States has become 
materially prohibited, as the tariff of said law exacts 75 cents gold. 



46 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

"In order to give you a practical idea of what is going on, I .send you tlie following 
comparative statistics : 

Actual Exportation, Possible Exportation, 

Crops. Carloads. Carloads. 

18S)9-1900 --.- 219 About 500 

1900-1901 274 600 

1901-1902 251 700 

1902-1903 220 800 

1903-K»04 186 900 

1904-1905 (to date) 119 1,000 

"The mentioned exportation was shipped in a majority of cases to Canada; a small 
part went to CananeaviaNogalesand Naco ; anothersraallparttothe State of Chihuahua 
via Ciudad Juarez, and some more to the United States. It is proved that only 20 of the 
carloads of this year went to the United States, and I do not think the whole export of 
this year to that country will be above 26 carloads. As it seems that there is no remedy 
for the evil that afflicts us, some owners of magnificent orchards in Guaymas and Her- 
mosillo are thinking of rooting out the numberless and beautiful orange trees which 
they planted about the time of the opening of this railroad in 1882, because in both 
places oranges are sold at 25 cents a hundred and there are but very few purchasers. 

" It must not be forgotten that the lumber and nails needed for the packing boxes, as 
well as the paper to wrap the oranges in, all come from the United States. 

" I have wearied you with all these data in order to inform you of the situation and also 
to beg you to do all you can, conveniently, so that in some way or other a remedy may 
be brought for the serious prejudice suffered by the growers of such an excellent fruit 
and at the same time by this transportation line." 

This I beg to submit to your superior knowledge as an answer to your favor of the 

3d inst. 

Yours very respectfully, 

(Signed:) S. CAMACHO. 

Answer, 

Mexico City, April 1, 1905. 

Sr. Pbof. A. L. Hereera, Commission of Parasitologia, Mexico, D. F.: 

Dear Sir: I beg to acknowledge the receipt of your communication of March 2.5th, 
which I have perused carefully, and, taking up your questions in their order, would 
respectfully reply as follows : 

First — As oranges are grown to a greater or less extent over the greater part of Mexico, 
it will be impossible, in the limited time at my disposal, to visit all the places in the 
Mexican Republic where the orange is grown. It is my desire, however, to visit other 
of the more important orange sections than those already seen, especially those in the 
tierra caliente, and the habitat of the Trypeta ludens. It is my desire, as it is to the 
interest of both countries concerned, to give this matter the fullest possible investiga- 
tion, in order that we may arrive at the actual truth in regard to the prevalence of the 
Trypeta ludens in Mexico, its extent, destructiveness, etc. In this matter I am certain, 
from the valuable aid which you have rendered me in the past, that I shall have your 
hearty cooperation. In furtherance of this work, I desire to visit, in the State of Vera 
Cruz, Cordova, Jalapa, and Vera Cruz ; in the State of Jalisco, Guadalajara and La 
Barca. In the completion of my work, 1 desire to visit all points in the State of Tamau- 
lipas and the vicinity of Tampico. 

Second — I am much gratified to have been asked this question, as it gives me an 
opportunity to acknowledge the valuable assistance which I have received from you. 
Nothing has been left undone on your part or that of your assistants to give me the 
fullest opportunity for a thorough investigation. Every request which I have made 
along these lines has been granted, and very many of my requirements have been 
anticipated. I have found in you a willing and able collaborator, and I owe the greater 
part of the knowledge I have obtained concerning the Irypeta ludens in Mexico to your 
valuable assistance, without which my efforts would have been surrounded with almost 
insurmountable difficulties. I will further add, that I am convinced that it is your 



REPORT ON THE TRYPETA LUDENS IN MEXICO. 47 

■desire, as it is also the desire of the Department of Fomento, which you represent, to 
have the entire truth regarding this pest made public, and to this end you have left no 
■avenue closed which would lead me to the desired information. 

Third — The belief that the horticulturists of California have placed an embargo on 
ilexican oranges, using the pest as an excuse, is an error. I assure you that nothing 
was ever farther from the policy of the State and the Department which I represent. 

Oranges in small lots were occasionally brought to San Francisco, and so long as 
they were free from pests, were passed by our horticultural quarantine officer. On one 
occasion a shipment of several boxes from Acapulco was found to be badly infested 
with worms. This shipment was condemned. Other shipments were found infested, 
and reports were made to our office of the pest being found in different parts of Mexico, 
especially along the line of the Mexican Central Railroad. It was these facts, and the 
dread of the introduction of this pest into our orange orchards, which led to the pro- 
mulgation of the decree prohibiting the importation of Mexican oranges into the State 
of California. From what I have been able to learn during my researches here, I 
incline to the belief that the infested fruit reported along the line of the Mexican Cen- 
tral and in northern Mexico, was not grown in the sections where it was reported, but 
found its way from infested portions of the tierra caliente. 

In regard to the statement that INIexican oranges are earlier than those of California, 
I can only say that our orange season is continuous and that there is no month in the 
year in which shipments of this fn;it are not made. Fruit ripens at different seasons 
in different parts of the State, and there are several varieties, as the Nave), Mediter- 
ranean Sweet, Valencia Late, etc., the ripening seasons of which so overlap that there is 
no break, in any part of the year, in the California orange season. 

When you consider that the California orange crop now reaches the important figure 
•of 30, 000 carloads annually, that it is one of the most important of our California indus- 
tries, that in it are invested millions of dollars of capital, and that upon it thousands of 
our people depend for their homes and their lives, you will understand why we are so 
cautious about the introduction of any threatening danger ; and if, through any inad- 
vertence on our part, there should be admitted a pest which should damage even ten 
per cent of the crop, it would entail inestimable losses upon our people and our State. 
You will understand from this that it is the dread of an unknown evil, and not the fear 
of competition with Mexican growers, which has led us to place this embargo upon the 
Mexican orange. 

Fourth— There is no embargo upon the importation of Mexican oranges into the 
United States, outside of California. California is the most important orange-growing 
State in the Union, and, outside of Florida, is practically the only one in which the fruit 
is grown in commercial quantities, so that there is no reason why the Mexican fruit 
should not be admitted to all other points. 

I think that, as stated in the communication of Sr. S. Camacho, a copy of which you 
have kindly furnished me, the present high tariff imposed by the United States Govern- 
ment on foreign oranges has more directly affected Mexican shippers than has the action 
of California. This, however, is a matter for the consideration of the United States 
Congress and one outside of my line. 

Personally I may say that, with the present methods of growing, handling, packing, 
and shipping oranges in vogue in Mexico, were the American import duty entirely 
removed there would be no possibility of the Mexican orange competing in the open 
market with that of California, so long as California could produce enough to supply 
the demand. 

Fifth—The statements made in this section are correct. Fearing the possibility of 
introducing the Trypeta ludenn into the California orchards, the State Board of Horti- 
culture prohibited the importation of the Mexican orange into the State, and the rail- 
roads running into it have refused to make a tariff on this fruit. Under the direction 
of Mr. Craw, all cars used for transportation of Mexican oranges are disinfected by 
steam before they can be used in the California trade. 

The orange-growers of California may have been unduly alarmed concerning the 
situation here, and it is the object of my present mission to ascertain all the truth and 
remove, as far as possible, such fears, if they are unfounded. This I shall do in a full 
report, wdiich will be published at as early a date as possible after my return. 



48 REPORT ON THE TRYPETA LUDENS IN MEXICO. 

Sijrth—l appreciate your very kind offer to forward to our quarantine department 
branches of fruiting orange trees, at different seasons, in order to convince us of the 
suiallness of the danger. Tliis is wholly unnecessary and would give you unneeded 
trouble. My observations and inquiries while in Mexico, aided as I have been by your 
valuable assistance, have given me the fullest possible information in this matter, and, 
while thanking you for the offer, I must decline putting you to so much additional and 
unnecessary trouble. 

In conclusion, I will state that I am convinced that the Department of Fomento, 
through the Commission of Pai'usitologia, and under your direction, has performed 
very intelligent and very thorough work, looking to the extermination of the Trypeta 
ludens pest in those sections where it is known to exist; that it is the desire of your 
department, equally with the California Commission of Horticulture, to prevent this • 
pest from being introduced into the United States, and that you are willing to cooperate 
with us in every way to this end. I believe, too, that our investigations will result in 
removing certain misunderstandings that have existed on the part of California 
growers as to the wide extent and destructiveness of the Trypeta ludens in Mexico, and, 
on the part of the Mexican growers, as to the fear of competition, by Californians, from 
Mexican fruit. I assure you that it has been from no feeling of jealousy regarding the 
Mexican fi'uit that California has acted, but .wholly from a desire to protect one of our 
greatest industries from what appeared to us a serious and threatening danger. 

Again thanking you for your valuable assistance and many courtesies which I have 
received, I have the honor to remain. 

Yours very sincerely, 

(Signed:) JOHN ISAAC, 

Special Commissioner. 

Communication from the Secretary of the Department of Fomento. 

Mexico City, April 8, 1905. 
To John Isaac, Esq., 

Special Commissioner of the Stale Commission of Horticulture of CaKJornia: 
Informed of the zeal you have displayed in the course of your investigations relative 
to the habitat of the Morelos worm (Trypeta ludens), its actual importance, the means 
used in fighting it, and the possibility of destroying the same; aware also of the tenor 
of the preliminary report which you address to Hon. Ell wood Cooper, President of the 
Board of Horticulture of California, giving him information upon the true importance 
of the plague, the Secretary of this Department thanks you for your work, trusting you 
will kindly transmit the expression of his gratitude to Hon. Ellwood Cooper and the 
Governor of California, with the understanding that this manifestation takes place 
through the official channel. 

(Signed:) ESCONTRIA, 
Secretary of the Department of Fomento. 

Answer. 

To the Honorable Secretary of the Department of Fomento — Present: 

HoNOKABLE SiB: I havc the honor to acknowledge the receipt of your communication 
No. 7981, wherein you ask me to transmit your thanks to the Hon. P^llwood Cooper and 
to the Governor of California, for the interest they have manifested in the study of the 
Mexican orange and the Trypeta ludens. 

In answer, 1 have the honor to inform you that I have great satisfaction and pleasure 
in forwarding copies of your communication to Hon. Ellwood Cooper and the Governor 
of California. For my own part, I give you my heartiest thanks for the attention of 
which I have been the object and the facilities that have been furnished me for my 
investigations. 

With the sentiments of the truest consideration, I remain. 

Very respectfully yours, 

JOHN ISAAC. 






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